diff --git a/README.md b/README.md
index 3825327..11da5e4 100644
--- a/README.md
+++ b/README.md
@@ -9,7 +9,7 @@ This pattern is often used for tagging containers.
 
 ## Example output
 
-The GitHub action's only output is named `tags` and is a JSON formatted list. See the example workflow below for details on how to convert the JSON formatted list to something else.
+The GitHub action's only output is named `tags` and is a JSON formatted list. See the example workflow below for details on how to convert the JSON formatted list to something else. Tags will always be in decreasing order of specificity.
 
 | Pushed reference | GitHub repo tags | `tags` output                        | Comment                                                                       |
 | ---------------- | ---------------- | ------------------------------------ | ----------------------------------------------------------------------------- |
@@ -22,9 +22,9 @@ The GitHub action's only output is named `tags` and is a JSON formatted list. Se
 | `1.2.3-alpha.1`  | `1.2.0`          | `"[1.2.3-alpha.1]"`                  | A pre-release suffix on a version is treated like a branch                    |
 | `1.2.3-4`        | `1.2.0`, `1.2.3` | `"[1.2.3-4, 1.2.3, 1.2, 1, latest]"` | A build number suffix on a version is treated like the version but even newer |
 
-## Required input parameters
+## Recommended input parameters
 
-- `githubToken`: The GitHub token, required so this action can fetch tags using the GitHub API.
+- `githubToken`: The GitHub token, required so this action can fetch tags using the GitHub API. If this parameter is not set then `defaultTag` (if set) or an empty list will be returned.
 
 ## Optional input parameters
 
@@ -33,6 +33,10 @@ The GitHub action's only output is named `tags` and is a JSON formatted list. Se
   This can be useful for running a workflow in pull requests where no suitable git references are present.
   `prefix` is _not_ automatically added.
 
+## Output parameters
+
+- `tags`: A JSON formatted list of calculated tags.
+
 ## Example workflow
 
 ```yaml
diff --git a/action.yml b/action.yml
index f1a49bc..b4c3d07 100644
--- a/action.yml
+++ b/action.yml
@@ -1,22 +1,36 @@
+# Reference: https://docs.github.com/en/actions/creating-actions/metadata-syntax-for-github-actions
+---
+author: Simon Li
 name: major-minor-tag-calculator
 description: Calculate major and minor semver tags, e.g. for tagging containers
-author: Simon Li
+
+# Manually keep the input-, and output- descriptions in sync with the readme!
 inputs:
   githubToken:
     required: false
-    description: GitHub token
+    description: |-
+      The GitHub token, required so this action can fetch tags using the GitHub API. If this parameter is not set then `defaultTag` (if set) or an empty list will be returned.
     default: ""
   prefix:
     required: false
-    description: Prefix each tag with this string, e.g. "docker/repository:"
+    description: |-
+      A string that each returned tag should be prefixed with, for example to tag a Docker container set this to `user/repository:`.
     default: ""
   defaultTag:
     required: false
-    description: If the tag output would be empty return this tag instead
+    description: |-
+      If the tag output would be empty return this tag instead.
+      This can be useful for running a workflow in pull requests where no suitable git references are present.
+      `prefix` is _not_ automatically added.
     default: ""
 outputs:
   tags:
-    description: List of calculated tags
+    description: A JSON formatted list of calculated tags.
+
 runs:
   using: node12
   main: dist/index.js
+
+branding:
+  icon: bookmark
+  color: purple