diff --git a/examples/chip-tool/commands/tests/TestCommand.h b/examples/chip-tool/commands/tests/TestCommand.h
index bb5d2b82cb7632..396835a1fdb03f 100644
--- a/examples/chip-tool/commands/tests/TestCommand.h
+++ b/examples/chip-tool/commands/tests/TestCommand.h
@@ -161,6 +161,8 @@ class TestCommand : public CHIPCommand
     template <typename T>
     bool CheckValueAsListLength(const char * itemName, chip::app::DataModel::DecodableList<T> list, uint64_t expectedLength)
     {
+        // We don't just use list.ComputeSize(), because we want to check that
+        // all the values in the list correctly decode to our type too.
         auto iter      = list.begin();
         uint64_t count = 0;
         while (iter.Next())
diff --git a/examples/chip-tool/templates/commands.zapt b/examples/chip-tool/templates/commands.zapt
index 635b955879b0c5..c6b5642cfa5673 100644
--- a/examples/chip-tool/templates/commands.zapt
+++ b/examples/chip-tool/templates/commands.zapt
@@ -139,16 +139,12 @@ static void On{{asUpperCamelCase parent.name}}{{asUpperCamelCase name}}ListAttri
     ModelCommand * command = static_cast<ModelCommand *>(context);
 
     size_t count = 0;
-    {
-      auto iter = list.begin();
-      while (iter.Next()) {
-        ++count;
-      }
-      if (iter.GetStatus() != CHIP_NO_ERROR) {
-        command->SetCommandExitStatus(iter.GetStatus());
-        return;
-      }
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR) {
+      command->SetCommandExitStatus(err);
+      return;
     }
+
     ChipLogProgress(chipTool, "On{{asUpperCamelCase parent.name}}{{asUpperCamelCase name}}ListAttributeResponse: %zu entries", count);
 
     auto iter = list.begin();
@@ -180,8 +176,7 @@ static void On{{asUpperCamelCase parent.name}}{{asUpperCamelCase name}}ListAttri
         {{/if}}
         {{/if}}
     }
-
-    command->SetCommandExitStatus(CHIP_NO_ERROR);
+    command->SetCommandExitStatus(iter.GetStatus());
 }
 
 {{/if}}
diff --git a/src/app/clusters/test-cluster-server/test-cluster-server.cpp b/src/app/clusters/test-cluster-server/test-cluster-server.cpp
index 01bec699d75ef7..b9b895bcee718a 100644
--- a/src/app/clusters/test-cluster-server/test-cluster-server.cpp
+++ b/src/app/clusters/test-cluster-server/test-cluster-server.cpp
@@ -394,15 +394,9 @@ bool emberAfTestClusterClusterTestListInt8UReverseRequestCallback(
     CommandHandler * commandObj, ConcreteCommandPath const & commandPath,
     Commands::TestListInt8UReverseRequest::DecodableType const & commandData)
 {
-    size_t count = 0;
-    {
-        auto iter = commandData.arg1.begin();
-        while (iter.Next())
-        {
-            ++count;
-        }
-        VerifyOrExit(iter.GetStatus() == CHIP_NO_ERROR, );
-    }
+    size_t count   = 0;
+    CHIP_ERROR err = commandData.arg1.ComputeSize(&count);
+    VerifyOrExit(err == CHIP_NO_ERROR, );
 
     {
         auto iter = commandData.arg1.begin();
diff --git a/src/app/data-model/DecodableList.h b/src/app/data-model/DecodableList.h
index 023b09b2abb65e..ac1075c9ab594f 100644
--- a/src/app/data-model/DecodableList.h
+++ b/src/app/data-model/DecodableList.h
@@ -127,6 +127,14 @@ class DecodableList
 
     Iterator begin() const { return Iterator(mReader); }
 
+    /*
+     * Compute the size of the list.  This can fail if the TLV is malformed.  If
+     * this succeeds, that does not guarantee that the individual items can be
+     * successfully decoded; consumers should check Iterator::GetStatus() when
+     * actually decoding them.
+     */
+    CHIP_ERROR ComputeSize(size_t * size) const { return mReader.CountRemainingInContainer(size); }
+
 private:
     TLV::TLVReader mReader;
 };
diff --git a/src/controller/python/chip/clusters/CHIPClusters.cpp b/src/controller/python/chip/clusters/CHIPClusters.cpp
index 8778d989815c4b..457049fd50bd64 100644
--- a/src/controller/python/chip/clusters/CHIPClusters.cpp
+++ b/src/controller/python/chip/clusters/CHIPClusters.cpp
@@ -105,12 +105,8 @@ static void OnApplicationLauncherApplicationLauncherListListAttributeResponse(vo
                                                                               const DataModel::DecodableList<uint16_t> & list)
 {
     uint16_t count = 0;
-    auto iter      = list.begin();
-    while (iter.Next())
-    {
-        ++count;
-    }
-    if (iter.GetStatus() != CHIP_NO_ERROR)
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
         if (gFailureResponseDelegate != nullptr)
         {
@@ -132,6 +128,14 @@ static void OnApplicationLauncherApplicationLauncherListListAttributeResponse(vo
 #endif // CHIP_PROGRESS_LOGGING
         ChipLogProgress(Zcl, "    %" PRIu16 ",", entry);
     }
+    if (iter.GetStatus() != CHIP_NO_ERROR)
+    {
+        if (gFailureResponseDelegate != nullptr)
+        {
+            gFailureResponseDelegate(EMBER_ZCL_STATUS_INVALID_VALUE);
+        }
+        return;
+    }
 
     if (count > 0)
         ChipLogProgress(Zcl, "  ]");
@@ -148,12 +152,8 @@ static void OnAudioOutputAudioOutputListListAttributeResponse(
     const DataModel::DecodableList<chip::app::Clusters::AudioOutput::Structs::AudioOutputInfo::DecodableType> & list)
 {
     uint16_t count = 0;
-    auto iter      = list.begin();
-    while (iter.Next())
-    {
-        ++count;
-    }
-    if (iter.GetStatus() != CHIP_NO_ERROR)
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
         if (gFailureResponseDelegate != nullptr)
         {
@@ -179,6 +179,14 @@ static void OnAudioOutputAudioOutputListListAttributeResponse(
         ChipLogProgress(Zcl, "      name: %.*s,", static_cast<int>(entry.name.size()), entry.name.data());
         ChipLogProgress(Zcl, "    },");
     }
+    if (iter.GetStatus() != CHIP_NO_ERROR)
+    {
+        if (gFailureResponseDelegate != nullptr)
+        {
+            gFailureResponseDelegate(EMBER_ZCL_STATUS_INVALID_VALUE);
+        }
+        return;
+    }
 
     if (count > 0)
         ChipLogProgress(Zcl, "  ]");
@@ -193,12 +201,8 @@ static void OnContentLauncherAcceptsHeaderListListAttributeResponse(void * conte
                                                                     const DataModel::DecodableList<chip::ByteSpan> & list)
 {
     uint16_t count = 0;
-    auto iter      = list.begin();
-    while (iter.Next())
-    {
-        ++count;
-    }
-    if (iter.GetStatus() != CHIP_NO_ERROR)
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
         if (gFailureResponseDelegate != nullptr)
         {
@@ -220,6 +224,14 @@ static void OnContentLauncherAcceptsHeaderListListAttributeResponse(void * conte
 #endif // CHIP_PROGRESS_LOGGING
         ChipLogProgress(Zcl, "    %s,", ByteSpanToString(entry).c_str());
     }
+    if (iter.GetStatus() != CHIP_NO_ERROR)
+    {
+        if (gFailureResponseDelegate != nullptr)
+        {
+            gFailureResponseDelegate(EMBER_ZCL_STATUS_INVALID_VALUE);
+        }
+        return;
+    }
 
     if (count > 0)
         ChipLogProgress(Zcl, "  ]");
@@ -233,12 +245,8 @@ static void OnContentLauncherSupportedStreamingTypesListAttributeResponse(
     void * context, const DataModel::DecodableList<chip::app::Clusters::ContentLauncher::ContentLaunchStreamingType> & list)
 {
     uint16_t count = 0;
-    auto iter      = list.begin();
-    while (iter.Next())
-    {
-        ++count;
-    }
-    if (iter.GetStatus() != CHIP_NO_ERROR)
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
         if (gFailureResponseDelegate != nullptr)
         {
@@ -260,6 +268,14 @@ static void OnContentLauncherSupportedStreamingTypesListAttributeResponse(
 #endif // CHIP_PROGRESS_LOGGING
         ChipLogProgress(Zcl, "    %" PRIu8 ",", entry);
     }
+    if (iter.GetStatus() != CHIP_NO_ERROR)
+    {
+        if (gFailureResponseDelegate != nullptr)
+        {
+            gFailureResponseDelegate(EMBER_ZCL_STATUS_INVALID_VALUE);
+        }
+        return;
+    }
 
     if (count > 0)
         ChipLogProgress(Zcl, "  ]");
@@ -274,12 +290,8 @@ static void OnDescriptorDeviceListListAttributeResponse(
     void * context, const DataModel::DecodableList<chip::app::Clusters::Descriptor::Structs::DeviceType::DecodableType> & list)
 {
     uint16_t count = 0;
-    auto iter      = list.begin();
-    while (iter.Next())
-    {
-        ++count;
-    }
-    if (iter.GetStatus() != CHIP_NO_ERROR)
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
         if (gFailureResponseDelegate != nullptr)
         {
@@ -304,6 +316,14 @@ static void OnDescriptorDeviceListListAttributeResponse(
         ChipLogProgress(Zcl, "      revision: %" PRIu16 ",", entry.revision);
         ChipLogProgress(Zcl, "    },");
     }
+    if (iter.GetStatus() != CHIP_NO_ERROR)
+    {
+        if (gFailureResponseDelegate != nullptr)
+        {
+            gFailureResponseDelegate(EMBER_ZCL_STATUS_INVALID_VALUE);
+        }
+        return;
+    }
 
     if (count > 0)
         ChipLogProgress(Zcl, "  ]");
@@ -317,12 +337,8 @@ chip::Callback::Callback<DescriptorDeviceListListAttributeCallback> gDescriptorD
 static void OnDescriptorServerListListAttributeResponse(void * context, const DataModel::DecodableList<chip::ClusterId> & list)
 {
     uint16_t count = 0;
-    auto iter      = list.begin();
-    while (iter.Next())
-    {
-        ++count;
-    }
-    if (iter.GetStatus() != CHIP_NO_ERROR)
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
         if (gFailureResponseDelegate != nullptr)
         {
@@ -344,6 +360,14 @@ static void OnDescriptorServerListListAttributeResponse(void * context, const Da
 #endif // CHIP_PROGRESS_LOGGING
         ChipLogProgress(Zcl, "    %" PRIu32 ",", entry);
     }
+    if (iter.GetStatus() != CHIP_NO_ERROR)
+    {
+        if (gFailureResponseDelegate != nullptr)
+        {
+            gFailureResponseDelegate(EMBER_ZCL_STATUS_INVALID_VALUE);
+        }
+        return;
+    }
 
     if (count > 0)
         ChipLogProgress(Zcl, "  ]");
@@ -357,12 +381,8 @@ chip::Callback::Callback<DescriptorServerListListAttributeCallback> gDescriptorS
 static void OnDescriptorClientListListAttributeResponse(void * context, const DataModel::DecodableList<chip::ClusterId> & list)
 {
     uint16_t count = 0;
-    auto iter      = list.begin();
-    while (iter.Next())
-    {
-        ++count;
-    }
-    if (iter.GetStatus() != CHIP_NO_ERROR)
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
         if (gFailureResponseDelegate != nullptr)
         {
@@ -384,6 +404,14 @@ static void OnDescriptorClientListListAttributeResponse(void * context, const Da
 #endif // CHIP_PROGRESS_LOGGING
         ChipLogProgress(Zcl, "    %" PRIu32 ",", entry);
     }
+    if (iter.GetStatus() != CHIP_NO_ERROR)
+    {
+        if (gFailureResponseDelegate != nullptr)
+        {
+            gFailureResponseDelegate(EMBER_ZCL_STATUS_INVALID_VALUE);
+        }
+        return;
+    }
 
     if (count > 0)
         ChipLogProgress(Zcl, "  ]");
@@ -397,12 +425,8 @@ chip::Callback::Callback<DescriptorClientListListAttributeCallback> gDescriptorC
 static void OnDescriptorPartsListListAttributeResponse(void * context, const DataModel::DecodableList<chip::EndpointId> & list)
 {
     uint16_t count = 0;
-    auto iter      = list.begin();
-    while (iter.Next())
-    {
-        ++count;
-    }
-    if (iter.GetStatus() != CHIP_NO_ERROR)
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
         if (gFailureResponseDelegate != nullptr)
         {
@@ -424,6 +448,14 @@ static void OnDescriptorPartsListListAttributeResponse(void * context, const Dat
 #endif // CHIP_PROGRESS_LOGGING
         ChipLogProgress(Zcl, "    %" PRIu16 ",", entry);
     }
+    if (iter.GetStatus() != CHIP_NO_ERROR)
+    {
+        if (gFailureResponseDelegate != nullptr)
+        {
+            gFailureResponseDelegate(EMBER_ZCL_STATUS_INVALID_VALUE);
+        }
+        return;
+    }
 
     if (count > 0)
         ChipLogProgress(Zcl, "  ]");
@@ -438,12 +470,8 @@ static void OnFixedLabelLabelListListAttributeResponse(
     void * context, const DataModel::DecodableList<chip::app::Clusters::FixedLabel::Structs::LabelStruct::DecodableType> & list)
 {
     uint16_t count = 0;
-    auto iter      = list.begin();
-    while (iter.Next())
-    {
-        ++count;
-    }
-    if (iter.GetStatus() != CHIP_NO_ERROR)
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
         if (gFailureResponseDelegate != nullptr)
         {
@@ -468,6 +496,14 @@ static void OnFixedLabelLabelListListAttributeResponse(
         ChipLogProgress(Zcl, "      value: %.*s,", static_cast<int>(entry.value.size()), entry.value.data());
         ChipLogProgress(Zcl, "    },");
     }
+    if (iter.GetStatus() != CHIP_NO_ERROR)
+    {
+        if (gFailureResponseDelegate != nullptr)
+        {
+            gFailureResponseDelegate(EMBER_ZCL_STATUS_INVALID_VALUE);
+        }
+        return;
+    }
 
     if (count > 0)
         ChipLogProgress(Zcl, "  ]");
@@ -484,12 +520,8 @@ static void OnGeneralCommissioningBasicCommissioningInfoListListAttributeRespons
         list)
 {
     uint16_t count = 0;
-    auto iter      = list.begin();
-    while (iter.Next())
-    {
-        ++count;
-    }
-    if (iter.GetStatus() != CHIP_NO_ERROR)
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
         if (gFailureResponseDelegate != nullptr)
         {
@@ -513,6 +545,14 @@ static void OnGeneralCommissioningBasicCommissioningInfoListListAttributeRespons
         ChipLogProgress(Zcl, "      FailSafeExpiryLengthMs: %" PRIu32 ",", entry.failSafeExpiryLengthMs);
         ChipLogProgress(Zcl, "    },");
     }
+    if (iter.GetStatus() != CHIP_NO_ERROR)
+    {
+        if (gFailureResponseDelegate != nullptr)
+        {
+            gFailureResponseDelegate(EMBER_ZCL_STATUS_INVALID_VALUE);
+        }
+        return;
+    }
 
     if (count > 0)
         ChipLogProgress(Zcl, "  ]");
@@ -529,12 +569,8 @@ static void OnGeneralDiagnosticsNetworkInterfacesListAttributeResponse(
     const DataModel::DecodableList<chip::app::Clusters::GeneralDiagnostics::Structs::NetworkInterfaceType::DecodableType> & list)
 {
     uint16_t count = 0;
-    auto iter      = list.begin();
-    while (iter.Next())
-    {
-        ++count;
-    }
-    if (iter.GetStatus() != CHIP_NO_ERROR)
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
         if (gFailureResponseDelegate != nullptr)
         {
@@ -563,6 +599,14 @@ static void OnGeneralDiagnosticsNetworkInterfacesListAttributeResponse(
         ChipLogProgress(Zcl, "      Type: %" PRIu8 ",", entry.type);
         ChipLogProgress(Zcl, "    },");
     }
+    if (iter.GetStatus() != CHIP_NO_ERROR)
+    {
+        if (gFailureResponseDelegate != nullptr)
+        {
+            gFailureResponseDelegate(EMBER_ZCL_STATUS_INVALID_VALUE);
+        }
+        return;
+    }
 
     if (count > 0)
         ChipLogProgress(Zcl, "  ]");
@@ -578,12 +622,8 @@ static void OnGroupKeyManagementGroupsListAttributeResponse(
     const DataModel::DecodableList<chip::app::Clusters::GroupKeyManagement::Structs::GroupState::DecodableType> & list)
 {
     uint16_t count = 0;
-    auto iter      = list.begin();
-    while (iter.Next())
-    {
-        ++count;
-    }
-    if (iter.GetStatus() != CHIP_NO_ERROR)
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
         if (gFailureResponseDelegate != nullptr)
         {
@@ -609,6 +649,14 @@ static void OnGroupKeyManagementGroupsListAttributeResponse(
         ChipLogProgress(Zcl, "      GroupKeySetIndex: %" PRIu16 ",", entry.groupKeySetIndex);
         ChipLogProgress(Zcl, "    },");
     }
+    if (iter.GetStatus() != CHIP_NO_ERROR)
+    {
+        if (gFailureResponseDelegate != nullptr)
+        {
+            gFailureResponseDelegate(EMBER_ZCL_STATUS_INVALID_VALUE);
+        }
+        return;
+    }
 
     if (count > 0)
         ChipLogProgress(Zcl, "  ]");
@@ -624,12 +672,8 @@ static void OnGroupKeyManagementGroupKeysListAttributeResponse(
     const DataModel::DecodableList<chip::app::Clusters::GroupKeyManagement::Structs::GroupKey::DecodableType> & list)
 {
     uint16_t count = 0;
-    auto iter      = list.begin();
-    while (iter.Next())
-    {
-        ++count;
-    }
-    if (iter.GetStatus() != CHIP_NO_ERROR)
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
         if (gFailureResponseDelegate != nullptr)
         {
@@ -657,6 +701,14 @@ static void OnGroupKeyManagementGroupKeysListAttributeResponse(
         ChipLogProgress(Zcl, "      GroupKeySecurityPolicy: %" PRIu8 ",", entry.groupKeySecurityPolicy);
         ChipLogProgress(Zcl, "    },");
     }
+    if (iter.GetStatus() != CHIP_NO_ERROR)
+    {
+        if (gFailureResponseDelegate != nullptr)
+        {
+            gFailureResponseDelegate(EMBER_ZCL_STATUS_INVALID_VALUE);
+        }
+        return;
+    }
 
     if (count > 0)
         ChipLogProgress(Zcl, "  ]");
@@ -671,12 +723,8 @@ static void OnMediaInputMediaInputListListAttributeResponse(
     void * context, const DataModel::DecodableList<chip::app::Clusters::MediaInput::Structs::MediaInputInfo::DecodableType> & list)
 {
     uint16_t count = 0;
-    auto iter      = list.begin();
-    while (iter.Next())
-    {
-        ++count;
-    }
-    if (iter.GetStatus() != CHIP_NO_ERROR)
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
         if (gFailureResponseDelegate != nullptr)
         {
@@ -703,6 +751,14 @@ static void OnMediaInputMediaInputListListAttributeResponse(
         ChipLogProgress(Zcl, "      description: %.*s,", static_cast<int>(entry.description.size()), entry.description.data());
         ChipLogProgress(Zcl, "    },");
     }
+    if (iter.GetStatus() != CHIP_NO_ERROR)
+    {
+        if (gFailureResponseDelegate != nullptr)
+        {
+            gFailureResponseDelegate(EMBER_ZCL_STATUS_INVALID_VALUE);
+        }
+        return;
+    }
 
     if (count > 0)
         ChipLogProgress(Zcl, "  ]");
@@ -718,12 +774,8 @@ static void OnOperationalCredentialsFabricsListListAttributeResponse(
     const DataModel::DecodableList<chip::app::Clusters::OperationalCredentials::Structs::FabricDescriptor::DecodableType> & list)
 {
     uint16_t count = 0;
-    auto iter      = list.begin();
-    while (iter.Next())
-    {
-        ++count;
-    }
-    if (iter.GetStatus() != CHIP_NO_ERROR)
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
         if (gFailureResponseDelegate != nullptr)
         {
@@ -752,6 +804,14 @@ static void OnOperationalCredentialsFabricsListListAttributeResponse(
         ChipLogProgress(Zcl, "      Label: %.*s,", static_cast<int>(entry.label.size()), entry.label.data());
         ChipLogProgress(Zcl, "    },");
     }
+    if (iter.GetStatus() != CHIP_NO_ERROR)
+    {
+        if (gFailureResponseDelegate != nullptr)
+        {
+            gFailureResponseDelegate(EMBER_ZCL_STATUS_INVALID_VALUE);
+        }
+        return;
+    }
 
     if (count > 0)
         ChipLogProgress(Zcl, "  ]");
@@ -764,12 +824,8 @@ chip::Callback::Callback<OperationalCredentialsFabricsListListAttributeCallback>
 static void OnPowerSourceActiveBatteryFaultsListAttributeResponse(void * context, const DataModel::DecodableList<uint8_t> & list)
 {
     uint16_t count = 0;
-    auto iter      = list.begin();
-    while (iter.Next())
-    {
-        ++count;
-    }
-    if (iter.GetStatus() != CHIP_NO_ERROR)
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
         if (gFailureResponseDelegate != nullptr)
         {
@@ -791,6 +847,14 @@ static void OnPowerSourceActiveBatteryFaultsListAttributeResponse(void * context
 #endif // CHIP_PROGRESS_LOGGING
         ChipLogProgress(Zcl, "    %" PRIu8 ",", entry);
     }
+    if (iter.GetStatus() != CHIP_NO_ERROR)
+    {
+        if (gFailureResponseDelegate != nullptr)
+        {
+            gFailureResponseDelegate(EMBER_ZCL_STATUS_INVALID_VALUE);
+        }
+        return;
+    }
 
     if (count > 0)
         ChipLogProgress(Zcl, "  ]");
@@ -805,12 +869,8 @@ static void OnTvChannelTvChannelListListAttributeResponse(
     void * context, const DataModel::DecodableList<chip::app::Clusters::TvChannel::Structs::TvChannelInfo::DecodableType> & list)
 {
     uint16_t count = 0;
-    auto iter      = list.begin();
-    while (iter.Next())
-    {
-        ++count;
-    }
-    if (iter.GetStatus() != CHIP_NO_ERROR)
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
         if (gFailureResponseDelegate != nullptr)
         {
@@ -839,6 +899,14 @@ static void OnTvChannelTvChannelListListAttributeResponse(
                         entry.affiliateCallSign.data());
         ChipLogProgress(Zcl, "    },");
     }
+    if (iter.GetStatus() != CHIP_NO_ERROR)
+    {
+        if (gFailureResponseDelegate != nullptr)
+        {
+            gFailureResponseDelegate(EMBER_ZCL_STATUS_INVALID_VALUE);
+        }
+        return;
+    }
 
     if (count > 0)
         ChipLogProgress(Zcl, "  ]");
@@ -854,12 +922,8 @@ static void OnTargetNavigatorTargetNavigatorListListAttributeResponse(
     const DataModel::DecodableList<chip::app::Clusters::TargetNavigator::Structs::NavigateTargetTargetInfo::DecodableType> & list)
 {
     uint16_t count = 0;
-    auto iter      = list.begin();
-    while (iter.Next())
-    {
-        ++count;
-    }
-    if (iter.GetStatus() != CHIP_NO_ERROR)
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
         if (gFailureResponseDelegate != nullptr)
         {
@@ -884,6 +948,14 @@ static void OnTargetNavigatorTargetNavigatorListListAttributeResponse(
         ChipLogProgress(Zcl, "      name: %.*s,", static_cast<int>(entry.name.size()), entry.name.data());
         ChipLogProgress(Zcl, "    },");
     }
+    if (iter.GetStatus() != CHIP_NO_ERROR)
+    {
+        if (gFailureResponseDelegate != nullptr)
+        {
+            gFailureResponseDelegate(EMBER_ZCL_STATUS_INVALID_VALUE);
+        }
+        return;
+    }
 
     if (count > 0)
         ChipLogProgress(Zcl, "  ]");
@@ -896,12 +968,8 @@ chip::Callback::Callback<TargetNavigatorTargetNavigatorListListAttributeCallback
 static void OnTestClusterListInt8uListAttributeResponse(void * context, const DataModel::DecodableList<uint8_t> & list)
 {
     uint16_t count = 0;
-    auto iter      = list.begin();
-    while (iter.Next())
-    {
-        ++count;
-    }
-    if (iter.GetStatus() != CHIP_NO_ERROR)
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
         if (gFailureResponseDelegate != nullptr)
         {
@@ -923,6 +991,14 @@ static void OnTestClusterListInt8uListAttributeResponse(void * context, const Da
 #endif // CHIP_PROGRESS_LOGGING
         ChipLogProgress(Zcl, "    %" PRIu8 ",", entry);
     }
+    if (iter.GetStatus() != CHIP_NO_ERROR)
+    {
+        if (gFailureResponseDelegate != nullptr)
+        {
+            gFailureResponseDelegate(EMBER_ZCL_STATUS_INVALID_VALUE);
+        }
+        return;
+    }
 
     if (count > 0)
         ChipLogProgress(Zcl, "  ]");
@@ -936,12 +1012,8 @@ chip::Callback::Callback<TestClusterListInt8uListAttributeCallback> gTestCluster
 static void OnTestClusterListOctetStringListAttributeResponse(void * context, const DataModel::DecodableList<chip::ByteSpan> & list)
 {
     uint16_t count = 0;
-    auto iter      = list.begin();
-    while (iter.Next())
-    {
-        ++count;
-    }
-    if (iter.GetStatus() != CHIP_NO_ERROR)
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
         if (gFailureResponseDelegate != nullptr)
         {
@@ -963,6 +1035,14 @@ static void OnTestClusterListOctetStringListAttributeResponse(void * context, co
 #endif // CHIP_PROGRESS_LOGGING
         ChipLogProgress(Zcl, "    %s,", ByteSpanToString(entry).c_str());
     }
+    if (iter.GetStatus() != CHIP_NO_ERROR)
+    {
+        if (gFailureResponseDelegate != nullptr)
+        {
+            gFailureResponseDelegate(EMBER_ZCL_STATUS_INVALID_VALUE);
+        }
+        return;
+    }
 
     if (count > 0)
         ChipLogProgress(Zcl, "  ]");
@@ -978,12 +1058,8 @@ static void OnTestClusterListStructOctetStringListAttributeResponse(
     const DataModel::DecodableList<chip::app::Clusters::TestCluster::Structs::TestListStructOctet::DecodableType> & list)
 {
     uint16_t count = 0;
-    auto iter      = list.begin();
-    while (iter.Next())
-    {
-        ++count;
-    }
-    if (iter.GetStatus() != CHIP_NO_ERROR)
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
         if (gFailureResponseDelegate != nullptr)
         {
@@ -1008,6 +1084,14 @@ static void OnTestClusterListStructOctetStringListAttributeResponse(
         ChipLogProgress(Zcl, "      operationalCert: %s,", ByteSpanToString(entry.operationalCert).c_str());
         ChipLogProgress(Zcl, "    },");
     }
+    if (iter.GetStatus() != CHIP_NO_ERROR)
+    {
+        if (gFailureResponseDelegate != nullptr)
+        {
+            gFailureResponseDelegate(EMBER_ZCL_STATUS_INVALID_VALUE);
+        }
+        return;
+    }
 
     if (count > 0)
         ChipLogProgress(Zcl, "  ]");
@@ -1022,12 +1106,8 @@ static void OnThreadNetworkDiagnosticsNeighborTableListListAttributeResponse(
     const DataModel::DecodableList<chip::app::Clusters::ThreadNetworkDiagnostics::Structs::NeighborTable::DecodableType> & list)
 {
     uint16_t count = 0;
-    auto iter      = list.begin();
-    while (iter.Next())
-    {
-        ++count;
-    }
-    if (iter.GetStatus() != CHIP_NO_ERROR)
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
         if (gFailureResponseDelegate != nullptr)
         {
@@ -1064,6 +1144,14 @@ static void OnThreadNetworkDiagnosticsNeighborTableListListAttributeResponse(
         ChipLogProgress(Zcl, "      IsChild: %d,", entry.isChild);
         ChipLogProgress(Zcl, "    },");
     }
+    if (iter.GetStatus() != CHIP_NO_ERROR)
+    {
+        if (gFailureResponseDelegate != nullptr)
+        {
+            gFailureResponseDelegate(EMBER_ZCL_STATUS_INVALID_VALUE);
+        }
+        return;
+    }
 
     if (count > 0)
         ChipLogProgress(Zcl, "  ]");
@@ -1080,12 +1168,8 @@ static void OnThreadNetworkDiagnosticsRouteTableListListAttributeResponse(
     const DataModel::DecodableList<chip::app::Clusters::ThreadNetworkDiagnostics::Structs::RouteTable::DecodableType> & list)
 {
     uint16_t count = 0;
-    auto iter      = list.begin();
-    while (iter.Next())
-    {
-        ++count;
-    }
-    if (iter.GetStatus() != CHIP_NO_ERROR)
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
         if (gFailureResponseDelegate != nullptr)
         {
@@ -1118,6 +1202,14 @@ static void OnThreadNetworkDiagnosticsRouteTableListListAttributeResponse(
         ChipLogProgress(Zcl, "      LinkEstablished: %d,", entry.linkEstablished);
         ChipLogProgress(Zcl, "    },");
     }
+    if (iter.GetStatus() != CHIP_NO_ERROR)
+    {
+        if (gFailureResponseDelegate != nullptr)
+        {
+            gFailureResponseDelegate(EMBER_ZCL_STATUS_INVALID_VALUE);
+        }
+        return;
+    }
 
     if (count > 0)
         ChipLogProgress(Zcl, "  ]");
@@ -1133,12 +1225,8 @@ static void OnThreadNetworkDiagnosticsSecurityPolicyListAttributeResponse(
     const DataModel::DecodableList<chip::app::Clusters::ThreadNetworkDiagnostics::Structs::SecurityPolicy::DecodableType> & list)
 {
     uint16_t count = 0;
-    auto iter      = list.begin();
-    while (iter.Next())
-    {
-        ++count;
-    }
-    if (iter.GetStatus() != CHIP_NO_ERROR)
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
         if (gFailureResponseDelegate != nullptr)
         {
@@ -1163,6 +1251,14 @@ static void OnThreadNetworkDiagnosticsSecurityPolicyListAttributeResponse(
         ChipLogProgress(Zcl, "      Flags: %" PRIu16 ",", entry.flags);
         ChipLogProgress(Zcl, "    },");
     }
+    if (iter.GetStatus() != CHIP_NO_ERROR)
+    {
+        if (gFailureResponseDelegate != nullptr)
+        {
+            gFailureResponseDelegate(EMBER_ZCL_STATUS_INVALID_VALUE);
+        }
+        return;
+    }
 
     if (count > 0)
         ChipLogProgress(Zcl, "  ]");
@@ -1179,12 +1275,8 @@ static void OnThreadNetworkDiagnosticsOperationalDatasetComponentsListAttributeR
         chip::app::Clusters::ThreadNetworkDiagnostics::Structs::OperationalDatasetComponents::DecodableType> & list)
 {
     uint16_t count = 0;
-    auto iter      = list.begin();
-    while (iter.Next())
-    {
-        ++count;
-    }
-    if (iter.GetStatus() != CHIP_NO_ERROR)
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
         if (gFailureResponseDelegate != nullptr)
         {
@@ -1219,6 +1311,14 @@ static void OnThreadNetworkDiagnosticsOperationalDatasetComponentsListAttributeR
         ChipLogProgress(Zcl, "      ChannelMaskPresent: %d,", entry.channelMaskPresent);
         ChipLogProgress(Zcl, "    },");
     }
+    if (iter.GetStatus() != CHIP_NO_ERROR)
+    {
+        if (gFailureResponseDelegate != nullptr)
+        {
+            gFailureResponseDelegate(EMBER_ZCL_STATUS_INVALID_VALUE);
+        }
+        return;
+    }
 
     if (count > 0)
         ChipLogProgress(Zcl, "  ]");
@@ -1234,12 +1334,8 @@ static void OnThreadNetworkDiagnosticsActiveNetworkFaultsListListAttributeRespon
     void * context, const DataModel::DecodableList<chip::app::Clusters::ThreadNetworkDiagnostics::NetworkFault> & list)
 {
     uint16_t count = 0;
-    auto iter      = list.begin();
-    while (iter.Next())
-    {
-        ++count;
-    }
-    if (iter.GetStatus() != CHIP_NO_ERROR)
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
         if (gFailureResponseDelegate != nullptr)
         {
@@ -1261,6 +1357,14 @@ static void OnThreadNetworkDiagnosticsActiveNetworkFaultsListListAttributeRespon
 #endif // CHIP_PROGRESS_LOGGING
         ChipLogProgress(Zcl, "    %" PRIu8 ",", entry);
     }
+    if (iter.GetStatus() != CHIP_NO_ERROR)
+    {
+        if (gFailureResponseDelegate != nullptr)
+        {
+            gFailureResponseDelegate(EMBER_ZCL_STATUS_INVALID_VALUE);
+        }
+        return;
+    }
 
     if (count > 0)
         ChipLogProgress(Zcl, "  ]");
diff --git a/src/controller/python/templates/python-CHIPClusters-cpp.zapt b/src/controller/python/templates/python-CHIPClusters-cpp.zapt
index f75cb2feea4717..8f04de284e56f0 100644
--- a/src/controller/python/templates/python-CHIPClusters-cpp.zapt
+++ b/src/controller/python/templates/python-CHIPClusters-cpp.zapt
@@ -91,12 +91,8 @@ void OnAttributeResponse<bool>(void * /* context */, bool value)
 static void On{{asUpperCamelCase parent.name}}{{asUpperCamelCase name}}ListAttributeResponse(void * context, const DataModel::DecodableList<{{zapTypeToDecodableClusterObjectType type ns=parent.name}}> & list)
 {
     uint16_t count = 0;
-    auto iter = list.begin();
-    while (iter.Next())
-    {
-        ++count;
-    }
-    if (iter.GetStatus() != CHIP_NO_ERROR)
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
         if (gFailureResponseDelegate != nullptr)
         {
@@ -136,6 +132,14 @@ static void On{{asUpperCamelCase parent.name}}{{asUpperCamelCase name}}ListAttri
         ChipLogProgress(Zcl, "    {{asPrintFormat type}},", entry);
         {{/if}}
     }
+    if (iter.GetStatus() != CHIP_NO_ERROR)
+    {
+        if (gFailureResponseDelegate != nullptr)
+        {
+            gFailureResponseDelegate(EMBER_ZCL_STATUS_INVALID_VALUE);
+        }
+        return;
+    }
 
     if (count > 0)
         ChipLogProgress(Zcl, "  ]");
diff --git a/src/lib/core/CHIPTLV.h b/src/lib/core/CHIPTLV.h
index 930607ddc74993..b7fd1115ce24e0 100644
--- a/src/lib/core/CHIPTLV.h
+++ b/src/lib/core/CHIPTLV.h
@@ -862,6 +862,15 @@ class DLL_EXPORT TLVReader
      */
     CHIP_ERROR FindElementWithTag(Tag tagInApiForm, TLVReader & destReader) const;
 
+    /**
+     * Count how many elements remain in the currently-open container.  Will
+     * fail with CHIP_ERROR_INCORRECT_STATE if not currently in a container.
+     *
+     * @param[out] On success, set to the number of items following the current
+     *             reader position in the container.
+     */
+    CHIP_ERROR CountRemainingInContainer(size_t * size) const;
+
     /**
      * The profile id to be used for profile tags encoded in implicit form.
      *
diff --git a/src/lib/core/CHIPTLVReader.cpp b/src/lib/core/CHIPTLVReader.cpp
index 6fb6ca06d803e8..31f67bf7d494e9 100644
--- a/src/lib/core/CHIPTLVReader.cpp
+++ b/src/lib/core/CHIPTLVReader.cpp
@@ -949,6 +949,28 @@ CHIP_ERROR TLVReader::FindElementWithTag(Tag tag, TLVReader & destReader) const
     return err;
 }
 
+CHIP_ERROR TLVReader::CountRemainingInContainer(size_t * size) const
+{
+    if (mContainerType == kTLVType_NotSpecified)
+    {
+        return CHIP_ERROR_INCORRECT_STATE;
+    }
+
+    TLVReader tempReader(*this);
+    size_t count = 0;
+    CHIP_ERROR err;
+    while ((err = tempReader.Next()) == CHIP_NO_ERROR)
+    {
+        ++count;
+    };
+    if (err == CHIP_END_OF_TLV)
+    {
+        *size = count;
+        return CHIP_NO_ERROR;
+    }
+    return err;
+}
+
 CHIP_ERROR ContiguousBufferTLVReader::OpenContainer(ContiguousBufferTLVReader & containerReader)
 {
     // We are going to initialize containerReader by calling our superclass
diff --git a/zzz_generated/chip-tool/zap-generated/cluster/Commands.h b/zzz_generated/chip-tool/zap-generated/cluster/Commands.h
index 3c89b0b6325385..983b3a320004e3 100644
--- a/zzz_generated/chip-tool/zap-generated/cluster/Commands.h
+++ b/zzz_generated/chip-tool/zap-generated/cluster/Commands.h
@@ -158,19 +158,14 @@ OnApplicationLauncherApplicationLauncherListListAttributeResponse(void * context
 {
     ModelCommand * command = static_cast<ModelCommand *>(context);
 
-    size_t count = 0;
+    size_t count   = 0;
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
-        auto iter = list.begin();
-        while (iter.Next())
-        {
-            ++count;
-        }
-        if (iter.GetStatus() != CHIP_NO_ERROR)
-        {
-            command->SetCommandExitStatus(iter.GetStatus());
-            return;
-        }
+        command->SetCommandExitStatus(err);
+        return;
     }
+
     ChipLogProgress(chipTool, "OnApplicationLauncherApplicationLauncherListListAttributeResponse: %zu entries", count);
 
     auto iter  = list.begin();
@@ -183,8 +178,7 @@ OnApplicationLauncherApplicationLauncherListListAttributeResponse(void * context
         ++i;
         ChipLogProgress(chipTool, "INT16U[%" PRIu16 "]: %" PRIu16 "", i, entry);
     }
-
-    command->SetCommandExitStatus(CHIP_NO_ERROR);
+    command->SetCommandExitStatus(iter.GetStatus());
 }
 
 static void OnAudioOutputAudioOutputListListAttributeResponse(
@@ -193,19 +187,14 @@ static void OnAudioOutputAudioOutputListListAttributeResponse(
 {
     ModelCommand * command = static_cast<ModelCommand *>(context);
 
-    size_t count = 0;
+    size_t count   = 0;
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
-        auto iter = list.begin();
-        while (iter.Next())
-        {
-            ++count;
-        }
-        if (iter.GetStatus() != CHIP_NO_ERROR)
-        {
-            command->SetCommandExitStatus(iter.GetStatus());
-            return;
-        }
+        command->SetCommandExitStatus(err);
+        return;
     }
+
     ChipLogProgress(chipTool, "OnAudioOutputAudioOutputListListAttributeResponse: %zu entries", count);
 
     auto iter  = list.begin();
@@ -221,8 +210,7 @@ static void OnAudioOutputAudioOutputListListAttributeResponse(
         ChipLogProgress(chipTool, "  outputType: %" PRIu8 "", entry.outputType);
         ChipLogProgress(Zcl, "  name: %.*s", static_cast<int>(entry.name.size()), entry.name.data());
     }
-
-    command->SetCommandExitStatus(CHIP_NO_ERROR);
+    command->SetCommandExitStatus(iter.GetStatus());
 }
 
 static void
@@ -231,19 +219,14 @@ OnContentLauncherAcceptsHeaderListListAttributeResponse(void * context,
 {
     ModelCommand * command = static_cast<ModelCommand *>(context);
 
-    size_t count = 0;
+    size_t count   = 0;
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
-        auto iter = list.begin();
-        while (iter.Next())
-        {
-            ++count;
-        }
-        if (iter.GetStatus() != CHIP_NO_ERROR)
-        {
-            command->SetCommandExitStatus(iter.GetStatus());
-            return;
-        }
+        command->SetCommandExitStatus(err);
+        return;
     }
+
     ChipLogProgress(chipTool, "OnContentLauncherAcceptsHeaderListListAttributeResponse: %zu entries", count);
 
     auto iter  = list.begin();
@@ -256,8 +239,7 @@ OnContentLauncherAcceptsHeaderListListAttributeResponse(void * context,
         ++i;
         ChipLogProgress(Zcl, "  : %zu", entry.size());
     }
-
-    command->SetCommandExitStatus(CHIP_NO_ERROR);
+    command->SetCommandExitStatus(iter.GetStatus());
 }
 
 static void OnContentLauncherSupportedStreamingTypesListAttributeResponse(
@@ -266,19 +248,14 @@ static void OnContentLauncherSupportedStreamingTypesListAttributeResponse(
 {
     ModelCommand * command = static_cast<ModelCommand *>(context);
 
-    size_t count = 0;
+    size_t count   = 0;
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
-        auto iter = list.begin();
-        while (iter.Next())
-        {
-            ++count;
-        }
-        if (iter.GetStatus() != CHIP_NO_ERROR)
-        {
-            command->SetCommandExitStatus(iter.GetStatus());
-            return;
-        }
+        command->SetCommandExitStatus(err);
+        return;
     }
+
     ChipLogProgress(chipTool, "OnContentLauncherSupportedStreamingTypesListAttributeResponse: %zu entries", count);
 
     auto iter  = list.begin();
@@ -291,8 +268,7 @@ static void OnContentLauncherSupportedStreamingTypesListAttributeResponse(
         ++i;
         ChipLogProgress(chipTool, "ContentLaunchStreamingType[%" PRIu16 "]: %" PRIu8 "", i, entry);
     }
-
-    command->SetCommandExitStatus(CHIP_NO_ERROR);
+    command->SetCommandExitStatus(iter.GetStatus());
 }
 
 static void OnDescriptorDeviceListListAttributeResponse(
@@ -301,19 +277,14 @@ static void OnDescriptorDeviceListListAttributeResponse(
 {
     ModelCommand * command = static_cast<ModelCommand *>(context);
 
-    size_t count = 0;
+    size_t count   = 0;
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
-        auto iter = list.begin();
-        while (iter.Next())
-        {
-            ++count;
-        }
-        if (iter.GetStatus() != CHIP_NO_ERROR)
-        {
-            command->SetCommandExitStatus(iter.GetStatus());
-            return;
-        }
+        command->SetCommandExitStatus(err);
+        return;
     }
+
     ChipLogProgress(chipTool, "OnDescriptorDeviceListListAttributeResponse: %zu entries", count);
 
     auto iter  = list.begin();
@@ -328,8 +299,7 @@ static void OnDescriptorDeviceListListAttributeResponse(
         ChipLogProgress(chipTool, "  type: %" PRIu32 "", entry.type);
         ChipLogProgress(chipTool, "  revision: %" PRIu16 "", entry.revision);
     }
-
-    command->SetCommandExitStatus(CHIP_NO_ERROR);
+    command->SetCommandExitStatus(iter.GetStatus());
 }
 
 static void OnDescriptorServerListListAttributeResponse(void * context,
@@ -337,19 +307,14 @@ static void OnDescriptorServerListListAttributeResponse(void * context,
 {
     ModelCommand * command = static_cast<ModelCommand *>(context);
 
-    size_t count = 0;
+    size_t count   = 0;
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
-        auto iter = list.begin();
-        while (iter.Next())
-        {
-            ++count;
-        }
-        if (iter.GetStatus() != CHIP_NO_ERROR)
-        {
-            command->SetCommandExitStatus(iter.GetStatus());
-            return;
-        }
+        command->SetCommandExitStatus(err);
+        return;
     }
+
     ChipLogProgress(chipTool, "OnDescriptorServerListListAttributeResponse: %zu entries", count);
 
     auto iter  = list.begin();
@@ -362,8 +327,7 @@ static void OnDescriptorServerListListAttributeResponse(void * context,
         ++i;
         ChipLogProgress(chipTool, "CLUSTER_ID[%" PRIu16 "]: %" PRIu32 "", i, entry);
     }
-
-    command->SetCommandExitStatus(CHIP_NO_ERROR);
+    command->SetCommandExitStatus(iter.GetStatus());
 }
 
 static void OnDescriptorClientListListAttributeResponse(void * context,
@@ -371,19 +335,14 @@ static void OnDescriptorClientListListAttributeResponse(void * context,
 {
     ModelCommand * command = static_cast<ModelCommand *>(context);
 
-    size_t count = 0;
+    size_t count   = 0;
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
-        auto iter = list.begin();
-        while (iter.Next())
-        {
-            ++count;
-        }
-        if (iter.GetStatus() != CHIP_NO_ERROR)
-        {
-            command->SetCommandExitStatus(iter.GetStatus());
-            return;
-        }
+        command->SetCommandExitStatus(err);
+        return;
     }
+
     ChipLogProgress(chipTool, "OnDescriptorClientListListAttributeResponse: %zu entries", count);
 
     auto iter  = list.begin();
@@ -396,8 +355,7 @@ static void OnDescriptorClientListListAttributeResponse(void * context,
         ++i;
         ChipLogProgress(chipTool, "CLUSTER_ID[%" PRIu16 "]: %" PRIu32 "", i, entry);
     }
-
-    command->SetCommandExitStatus(CHIP_NO_ERROR);
+    command->SetCommandExitStatus(iter.GetStatus());
 }
 
 static void OnDescriptorPartsListListAttributeResponse(void * context,
@@ -405,19 +363,14 @@ static void OnDescriptorPartsListListAttributeResponse(void * context,
 {
     ModelCommand * command = static_cast<ModelCommand *>(context);
 
-    size_t count = 0;
+    size_t count   = 0;
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
-        auto iter = list.begin();
-        while (iter.Next())
-        {
-            ++count;
-        }
-        if (iter.GetStatus() != CHIP_NO_ERROR)
-        {
-            command->SetCommandExitStatus(iter.GetStatus());
-            return;
-        }
+        command->SetCommandExitStatus(err);
+        return;
     }
+
     ChipLogProgress(chipTool, "OnDescriptorPartsListListAttributeResponse: %zu entries", count);
 
     auto iter  = list.begin();
@@ -430,8 +383,7 @@ static void OnDescriptorPartsListListAttributeResponse(void * context,
         ++i;
         ChipLogProgress(chipTool, "ENDPOINT_NO[%" PRIu16 "]: %" PRIu16 "", i, entry);
     }
-
-    command->SetCommandExitStatus(CHIP_NO_ERROR);
+    command->SetCommandExitStatus(iter.GetStatus());
 }
 
 static void OnFixedLabelLabelListListAttributeResponse(
@@ -440,19 +392,14 @@ static void OnFixedLabelLabelListListAttributeResponse(
 {
     ModelCommand * command = static_cast<ModelCommand *>(context);
 
-    size_t count = 0;
+    size_t count   = 0;
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
-        auto iter = list.begin();
-        while (iter.Next())
-        {
-            ++count;
-        }
-        if (iter.GetStatus() != CHIP_NO_ERROR)
-        {
-            command->SetCommandExitStatus(iter.GetStatus());
-            return;
-        }
+        command->SetCommandExitStatus(err);
+        return;
     }
+
     ChipLogProgress(chipTool, "OnFixedLabelLabelListListAttributeResponse: %zu entries", count);
 
     auto iter  = list.begin();
@@ -467,8 +414,7 @@ static void OnFixedLabelLabelListListAttributeResponse(
         ChipLogProgress(Zcl, "  label: %.*s", static_cast<int>(entry.label.size()), entry.label.data());
         ChipLogProgress(Zcl, "  value: %.*s", static_cast<int>(entry.value.size()), entry.value.data());
     }
-
-    command->SetCommandExitStatus(CHIP_NO_ERROR);
+    command->SetCommandExitStatus(iter.GetStatus());
 }
 
 static void OnGeneralCommissioningBasicCommissioningInfoListListAttributeResponse(
@@ -478,19 +424,14 @@ static void OnGeneralCommissioningBasicCommissioningInfoListListAttributeRespons
 {
     ModelCommand * command = static_cast<ModelCommand *>(context);
 
-    size_t count = 0;
+    size_t count   = 0;
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
-        auto iter = list.begin();
-        while (iter.Next())
-        {
-            ++count;
-        }
-        if (iter.GetStatus() != CHIP_NO_ERROR)
-        {
-            command->SetCommandExitStatus(iter.GetStatus());
-            return;
-        }
+        command->SetCommandExitStatus(err);
+        return;
     }
+
     ChipLogProgress(chipTool, "OnGeneralCommissioningBasicCommissioningInfoListListAttributeResponse: %zu entries", count);
 
     auto iter  = list.begin();
@@ -504,8 +445,7 @@ static void OnGeneralCommissioningBasicCommissioningInfoListListAttributeRespons
         ChipLogProgress(chipTool, "BasicCommissioningInfoType[%" PRIu16 "]:", i);
         ChipLogProgress(chipTool, "  failSafeExpiryLengthMs: %" PRIu32 "", entry.failSafeExpiryLengthMs);
     }
-
-    command->SetCommandExitStatus(CHIP_NO_ERROR);
+    command->SetCommandExitStatus(iter.GetStatus());
 }
 
 static void OnGeneralDiagnosticsNetworkInterfacesListAttributeResponse(
@@ -515,19 +455,14 @@ static void OnGeneralDiagnosticsNetworkInterfacesListAttributeResponse(
 {
     ModelCommand * command = static_cast<ModelCommand *>(context);
 
-    size_t count = 0;
+    size_t count   = 0;
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
-        auto iter = list.begin();
-        while (iter.Next())
-        {
-            ++count;
-        }
-        if (iter.GetStatus() != CHIP_NO_ERROR)
-        {
-            command->SetCommandExitStatus(iter.GetStatus());
-            return;
-        }
+        command->SetCommandExitStatus(err);
+        return;
     }
+
     ChipLogProgress(chipTool, "OnGeneralDiagnosticsNetworkInterfacesListAttributeResponse: %zu entries", count);
 
     auto iter  = list.begin();
@@ -546,8 +481,7 @@ static void OnGeneralDiagnosticsNetworkInterfacesListAttributeResponse(
         ChipLogProgress(Zcl, "  HardwareAddress: %zu", entry.hardwareAddress.size());
         ChipLogProgress(chipTool, "  type: %" PRIu8 "", entry.type);
     }
-
-    command->SetCommandExitStatus(CHIP_NO_ERROR);
+    command->SetCommandExitStatus(iter.GetStatus());
 }
 
 static void OnGroupKeyManagementGroupsListAttributeResponse(
@@ -556,19 +490,14 @@ static void OnGroupKeyManagementGroupsListAttributeResponse(
 {
     ModelCommand * command = static_cast<ModelCommand *>(context);
 
-    size_t count = 0;
+    size_t count   = 0;
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
-        auto iter = list.begin();
-        while (iter.Next())
-        {
-            ++count;
-        }
-        if (iter.GetStatus() != CHIP_NO_ERROR)
-        {
-            command->SetCommandExitStatus(iter.GetStatus());
-            return;
-        }
+        command->SetCommandExitStatus(err);
+        return;
     }
+
     ChipLogProgress(chipTool, "OnGroupKeyManagementGroupsListAttributeResponse: %zu entries", count);
 
     auto iter  = list.begin();
@@ -584,8 +513,7 @@ static void OnGroupKeyManagementGroupsListAttributeResponse(
         ChipLogProgress(chipTool, "  vendorGroupId: %" PRIu16 "", entry.vendorGroupId);
         ChipLogProgress(chipTool, "  groupKeySetIndex: %" PRIu16 "", entry.groupKeySetIndex);
     }
-
-    command->SetCommandExitStatus(CHIP_NO_ERROR);
+    command->SetCommandExitStatus(iter.GetStatus());
 }
 
 static void OnGroupKeyManagementGroupKeysListAttributeResponse(
@@ -594,19 +522,14 @@ static void OnGroupKeyManagementGroupKeysListAttributeResponse(
 {
     ModelCommand * command = static_cast<ModelCommand *>(context);
 
-    size_t count = 0;
+    size_t count   = 0;
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
-        auto iter = list.begin();
-        while (iter.Next())
-        {
-            ++count;
-        }
-        if (iter.GetStatus() != CHIP_NO_ERROR)
-        {
-            command->SetCommandExitStatus(iter.GetStatus());
-            return;
-        }
+        command->SetCommandExitStatus(err);
+        return;
     }
+
     ChipLogProgress(chipTool, "OnGroupKeyManagementGroupKeysListAttributeResponse: %zu entries", count);
 
     auto iter  = list.begin();
@@ -624,8 +547,7 @@ static void OnGroupKeyManagementGroupKeysListAttributeResponse(
         ChipLogProgress(chipTool, "  groupKeyEpochStartTime: %" PRIu64 "", entry.groupKeyEpochStartTime);
         ChipLogProgress(chipTool, "  groupKeySecurityPolicy: %" PRIu8 "", entry.groupKeySecurityPolicy);
     }
-
-    command->SetCommandExitStatus(CHIP_NO_ERROR);
+    command->SetCommandExitStatus(iter.GetStatus());
 }
 
 static void OnMediaInputMediaInputListListAttributeResponse(
@@ -634,19 +556,14 @@ static void OnMediaInputMediaInputListListAttributeResponse(
 {
     ModelCommand * command = static_cast<ModelCommand *>(context);
 
-    size_t count = 0;
+    size_t count   = 0;
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
-        auto iter = list.begin();
-        while (iter.Next())
-        {
-            ++count;
-        }
-        if (iter.GetStatus() != CHIP_NO_ERROR)
-        {
-            command->SetCommandExitStatus(iter.GetStatus());
-            return;
-        }
+        command->SetCommandExitStatus(err);
+        return;
     }
+
     ChipLogProgress(chipTool, "OnMediaInputMediaInputListListAttributeResponse: %zu entries", count);
 
     auto iter  = list.begin();
@@ -663,8 +580,7 @@ static void OnMediaInputMediaInputListListAttributeResponse(
         ChipLogProgress(Zcl, "  name: %.*s", static_cast<int>(entry.name.size()), entry.name.data());
         ChipLogProgress(Zcl, "  description: %.*s", static_cast<int>(entry.description.size()), entry.description.data());
     }
-
-    command->SetCommandExitStatus(CHIP_NO_ERROR);
+    command->SetCommandExitStatus(iter.GetStatus());
 }
 
 static void OnOperationalCredentialsFabricsListListAttributeResponse(
@@ -674,19 +590,14 @@ static void OnOperationalCredentialsFabricsListListAttributeResponse(
 {
     ModelCommand * command = static_cast<ModelCommand *>(context);
 
-    size_t count = 0;
+    size_t count   = 0;
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
-        auto iter = list.begin();
-        while (iter.Next())
-        {
-            ++count;
-        }
-        if (iter.GetStatus() != CHIP_NO_ERROR)
-        {
-            command->SetCommandExitStatus(iter.GetStatus());
-            return;
-        }
+        command->SetCommandExitStatus(err);
+        return;
     }
+
     ChipLogProgress(chipTool, "OnOperationalCredentialsFabricsListListAttributeResponse: %zu entries", count);
 
     auto iter  = list.begin();
@@ -705,8 +616,7 @@ static void OnOperationalCredentialsFabricsListListAttributeResponse(
         ChipLogProgress(chipTool, "  nodeId: %" PRIu64 "", entry.nodeId);
         ChipLogProgress(Zcl, "  Label: %.*s", static_cast<int>(entry.label.size()), entry.label.data());
     }
-
-    command->SetCommandExitStatus(CHIP_NO_ERROR);
+    command->SetCommandExitStatus(iter.GetStatus());
 }
 
 static void OnPowerSourceActiveBatteryFaultsListAttributeResponse(void * context,
@@ -714,19 +624,14 @@ static void OnPowerSourceActiveBatteryFaultsListAttributeResponse(void * context
 {
     ModelCommand * command = static_cast<ModelCommand *>(context);
 
-    size_t count = 0;
+    size_t count   = 0;
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
-        auto iter = list.begin();
-        while (iter.Next())
-        {
-            ++count;
-        }
-        if (iter.GetStatus() != CHIP_NO_ERROR)
-        {
-            command->SetCommandExitStatus(iter.GetStatus());
-            return;
-        }
+        command->SetCommandExitStatus(err);
+        return;
     }
+
     ChipLogProgress(chipTool, "OnPowerSourceActiveBatteryFaultsListAttributeResponse: %zu entries", count);
 
     auto iter  = list.begin();
@@ -739,8 +644,7 @@ static void OnPowerSourceActiveBatteryFaultsListAttributeResponse(void * context
         ++i;
         ChipLogProgress(chipTool, "ENUM8[%" PRIu16 "]: %" PRIu8 "", i, entry);
     }
-
-    command->SetCommandExitStatus(CHIP_NO_ERROR);
+    command->SetCommandExitStatus(iter.GetStatus());
 }
 
 static void OnTvChannelTvChannelListListAttributeResponse(
@@ -749,19 +653,14 @@ static void OnTvChannelTvChannelListListAttributeResponse(
 {
     ModelCommand * command = static_cast<ModelCommand *>(context);
 
-    size_t count = 0;
+    size_t count   = 0;
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
-        auto iter = list.begin();
-        while (iter.Next())
-        {
-            ++count;
-        }
-        if (iter.GetStatus() != CHIP_NO_ERROR)
-        {
-            command->SetCommandExitStatus(iter.GetStatus());
-            return;
-        }
+        command->SetCommandExitStatus(err);
+        return;
     }
+
     ChipLogProgress(chipTool, "OnTvChannelTvChannelListListAttributeResponse: %zu entries", count);
 
     auto iter  = list.begin();
@@ -780,8 +679,7 @@ static void OnTvChannelTvChannelListListAttributeResponse(
         ChipLogProgress(Zcl, "  affiliateCallSign: %.*s", static_cast<int>(entry.affiliateCallSign.size()),
                         entry.affiliateCallSign.data());
     }
-
-    command->SetCommandExitStatus(CHIP_NO_ERROR);
+    command->SetCommandExitStatus(iter.GetStatus());
 }
 
 static void OnTargetNavigatorTargetNavigatorListListAttributeResponse(
@@ -791,19 +689,14 @@ static void OnTargetNavigatorTargetNavigatorListListAttributeResponse(
 {
     ModelCommand * command = static_cast<ModelCommand *>(context);
 
-    size_t count = 0;
+    size_t count   = 0;
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
-        auto iter = list.begin();
-        while (iter.Next())
-        {
-            ++count;
-        }
-        if (iter.GetStatus() != CHIP_NO_ERROR)
-        {
-            command->SetCommandExitStatus(iter.GetStatus());
-            return;
-        }
+        command->SetCommandExitStatus(err);
+        return;
     }
+
     ChipLogProgress(chipTool, "OnTargetNavigatorTargetNavigatorListListAttributeResponse: %zu entries", count);
 
     auto iter  = list.begin();
@@ -818,27 +711,21 @@ static void OnTargetNavigatorTargetNavigatorListListAttributeResponse(
         ChipLogProgress(chipTool, "  identifier: %" PRIu8 "", entry.identifier);
         ChipLogProgress(Zcl, "  name: %.*s", static_cast<int>(entry.name.size()), entry.name.data());
     }
-
-    command->SetCommandExitStatus(CHIP_NO_ERROR);
+    command->SetCommandExitStatus(iter.GetStatus());
 }
 
 static void OnTestClusterListInt8uListAttributeResponse(void * context, const chip::app::DataModel::DecodableList<uint8_t> & list)
 {
     ModelCommand * command = static_cast<ModelCommand *>(context);
 
-    size_t count = 0;
+    size_t count   = 0;
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
-        auto iter = list.begin();
-        while (iter.Next())
-        {
-            ++count;
-        }
-        if (iter.GetStatus() != CHIP_NO_ERROR)
-        {
-            command->SetCommandExitStatus(iter.GetStatus());
-            return;
-        }
+        command->SetCommandExitStatus(err);
+        return;
     }
+
     ChipLogProgress(chipTool, "OnTestClusterListInt8uListAttributeResponse: %zu entries", count);
 
     auto iter  = list.begin();
@@ -851,8 +738,7 @@ static void OnTestClusterListInt8uListAttributeResponse(void * context, const ch
         ++i;
         ChipLogProgress(chipTool, "INT8U[%" PRIu16 "]: %" PRIu8 "", i, entry);
     }
-
-    command->SetCommandExitStatus(CHIP_NO_ERROR);
+    command->SetCommandExitStatus(iter.GetStatus());
 }
 
 static void OnTestClusterListOctetStringListAttributeResponse(void * context,
@@ -860,19 +746,14 @@ static void OnTestClusterListOctetStringListAttributeResponse(void * context,
 {
     ModelCommand * command = static_cast<ModelCommand *>(context);
 
-    size_t count = 0;
+    size_t count   = 0;
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
-        auto iter = list.begin();
-        while (iter.Next())
-        {
-            ++count;
-        }
-        if (iter.GetStatus() != CHIP_NO_ERROR)
-        {
-            command->SetCommandExitStatus(iter.GetStatus());
-            return;
-        }
+        command->SetCommandExitStatus(err);
+        return;
     }
+
     ChipLogProgress(chipTool, "OnTestClusterListOctetStringListAttributeResponse: %zu entries", count);
 
     auto iter  = list.begin();
@@ -885,8 +766,7 @@ static void OnTestClusterListOctetStringListAttributeResponse(void * context,
         ++i;
         ChipLogProgress(Zcl, "  : %zu", entry.size());
     }
-
-    command->SetCommandExitStatus(CHIP_NO_ERROR);
+    command->SetCommandExitStatus(iter.GetStatus());
 }
 
 static void OnTestClusterListStructOctetStringListAttributeResponse(
@@ -895,19 +775,14 @@ static void OnTestClusterListStructOctetStringListAttributeResponse(
 {
     ModelCommand * command = static_cast<ModelCommand *>(context);
 
-    size_t count = 0;
+    size_t count   = 0;
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
-        auto iter = list.begin();
-        while (iter.Next())
-        {
-            ++count;
-        }
-        if (iter.GetStatus() != CHIP_NO_ERROR)
-        {
-            command->SetCommandExitStatus(iter.GetStatus());
-            return;
-        }
+        command->SetCommandExitStatus(err);
+        return;
     }
+
     ChipLogProgress(chipTool, "OnTestClusterListStructOctetStringListAttributeResponse: %zu entries", count);
 
     auto iter  = list.begin();
@@ -922,8 +797,7 @@ static void OnTestClusterListStructOctetStringListAttributeResponse(
         ChipLogProgress(chipTool, "  fabricIndex: %" PRIu64 "", entry.fabricIndex);
         ChipLogProgress(Zcl, "  operationalCert: %zu", entry.operationalCert.size());
     }
-
-    command->SetCommandExitStatus(CHIP_NO_ERROR);
+    command->SetCommandExitStatus(iter.GetStatus());
 }
 
 static void OnThreadNetworkDiagnosticsNeighborTableListListAttributeResponse(
@@ -933,19 +807,14 @@ static void OnThreadNetworkDiagnosticsNeighborTableListListAttributeResponse(
 {
     ModelCommand * command = static_cast<ModelCommand *>(context);
 
-    size_t count = 0;
+    size_t count   = 0;
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
-        auto iter = list.begin();
-        while (iter.Next())
-        {
-            ++count;
-        }
-        if (iter.GetStatus() != CHIP_NO_ERROR)
-        {
-            command->SetCommandExitStatus(iter.GetStatus());
-            return;
-        }
+        command->SetCommandExitStatus(err);
+        return;
     }
+
     ChipLogProgress(chipTool, "OnThreadNetworkDiagnosticsNeighborTableListListAttributeResponse: %zu entries", count);
 
     auto iter  = list.begin();
@@ -972,8 +841,7 @@ static void OnThreadNetworkDiagnosticsNeighborTableListListAttributeResponse(
         ChipLogProgress(chipTool, "  fullNetworkData: %d", entry.fullNetworkData);
         ChipLogProgress(chipTool, "  isChild: %d", entry.isChild);
     }
-
-    command->SetCommandExitStatus(CHIP_NO_ERROR);
+    command->SetCommandExitStatus(iter.GetStatus());
 }
 
 static void OnThreadNetworkDiagnosticsRouteTableListListAttributeResponse(
@@ -983,19 +851,14 @@ static void OnThreadNetworkDiagnosticsRouteTableListListAttributeResponse(
 {
     ModelCommand * command = static_cast<ModelCommand *>(context);
 
-    size_t count = 0;
+    size_t count   = 0;
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
-        auto iter = list.begin();
-        while (iter.Next())
-        {
-            ++count;
-        }
-        if (iter.GetStatus() != CHIP_NO_ERROR)
-        {
-            command->SetCommandExitStatus(iter.GetStatus());
-            return;
-        }
+        command->SetCommandExitStatus(err);
+        return;
     }
+
     ChipLogProgress(chipTool, "OnThreadNetworkDiagnosticsRouteTableListListAttributeResponse: %zu entries", count);
 
     auto iter  = list.begin();
@@ -1018,8 +881,7 @@ static void OnThreadNetworkDiagnosticsRouteTableListListAttributeResponse(
         ChipLogProgress(chipTool, "  allocated: %d", entry.allocated);
         ChipLogProgress(chipTool, "  linkEstablished: %d", entry.linkEstablished);
     }
-
-    command->SetCommandExitStatus(CHIP_NO_ERROR);
+    command->SetCommandExitStatus(iter.GetStatus());
 }
 
 static void OnThreadNetworkDiagnosticsSecurityPolicyListAttributeResponse(
@@ -1029,19 +891,14 @@ static void OnThreadNetworkDiagnosticsSecurityPolicyListAttributeResponse(
 {
     ModelCommand * command = static_cast<ModelCommand *>(context);
 
-    size_t count = 0;
+    size_t count   = 0;
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
-        auto iter = list.begin();
-        while (iter.Next())
-        {
-            ++count;
-        }
-        if (iter.GetStatus() != CHIP_NO_ERROR)
-        {
-            command->SetCommandExitStatus(iter.GetStatus());
-            return;
-        }
+        command->SetCommandExitStatus(err);
+        return;
     }
+
     ChipLogProgress(chipTool, "OnThreadNetworkDiagnosticsSecurityPolicyListAttributeResponse: %zu entries", count);
 
     auto iter  = list.begin();
@@ -1056,8 +913,7 @@ static void OnThreadNetworkDiagnosticsSecurityPolicyListAttributeResponse(
         ChipLogProgress(chipTool, "  rotationTime: %" PRIu16 "", entry.rotationTime);
         ChipLogProgress(chipTool, "  flags: %" PRIu16 "", entry.flags);
     }
-
-    command->SetCommandExitStatus(CHIP_NO_ERROR);
+    command->SetCommandExitStatus(iter.GetStatus());
 }
 
 static void OnThreadNetworkDiagnosticsOperationalDatasetComponentsListAttributeResponse(
@@ -1067,19 +923,14 @@ static void OnThreadNetworkDiagnosticsOperationalDatasetComponentsListAttributeR
 {
     ModelCommand * command = static_cast<ModelCommand *>(context);
 
-    size_t count = 0;
+    size_t count   = 0;
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
-        auto iter = list.begin();
-        while (iter.Next())
-        {
-            ++count;
-        }
-        if (iter.GetStatus() != CHIP_NO_ERROR)
-        {
-            command->SetCommandExitStatus(iter.GetStatus());
-            return;
-        }
+        command->SetCommandExitStatus(err);
+        return;
     }
+
     ChipLogProgress(chipTool, "OnThreadNetworkDiagnosticsOperationalDatasetComponentsListAttributeResponse: %zu entries", count);
 
     auto iter  = list.begin();
@@ -1104,8 +955,7 @@ static void OnThreadNetworkDiagnosticsOperationalDatasetComponentsListAttributeR
         ChipLogProgress(chipTool, "  securityPolicyPresent: %d", entry.securityPolicyPresent);
         ChipLogProgress(chipTool, "  channelMaskPresent: %d", entry.channelMaskPresent);
     }
-
-    command->SetCommandExitStatus(CHIP_NO_ERROR);
+    command->SetCommandExitStatus(iter.GetStatus());
 }
 
 static void OnThreadNetworkDiagnosticsActiveNetworkFaultsListListAttributeResponse(
@@ -1113,19 +963,14 @@ static void OnThreadNetworkDiagnosticsActiveNetworkFaultsListListAttributeRespon
 {
     ModelCommand * command = static_cast<ModelCommand *>(context);
 
-    size_t count = 0;
+    size_t count   = 0;
+    CHIP_ERROR err = list.ComputeSize(&count);
+    if (err != CHIP_NO_ERROR)
     {
-        auto iter = list.begin();
-        while (iter.Next())
-        {
-            ++count;
-        }
-        if (iter.GetStatus() != CHIP_NO_ERROR)
-        {
-            command->SetCommandExitStatus(iter.GetStatus());
-            return;
-        }
+        command->SetCommandExitStatus(err);
+        return;
     }
+
     ChipLogProgress(chipTool, "OnThreadNetworkDiagnosticsActiveNetworkFaultsListListAttributeResponse: %zu entries", count);
 
     auto iter  = list.begin();
@@ -1138,8 +983,7 @@ static void OnThreadNetworkDiagnosticsActiveNetworkFaultsListListAttributeRespon
         ++i;
         ChipLogProgress(chipTool, "NetworkFault[%" PRIu16 "]: %" PRIu8 "", i, entry);
     }
-
-    command->SetCommandExitStatus(CHIP_NO_ERROR);
+    command->SetCommandExitStatus(iter.GetStatus());
 }
 
 static void OnAccountLoginGetSetupPINResponseSuccess(