chore: Add tool rules example

[mattzh72]

Add tool rules example. Ran it successfully e2e:

(base) (letta-py3.12) mattzhou@Matts-MacBook-Pro MemGPT % poetry run python /Users/mattzhou/MemGPT/examples/tool_rule_usage.py
Initializing database...
Deleted agent: a407bebb-bd5c-5bcb-8c8d-1416385c76f3 with ID agent-2ab5503a-8b5f-481b-a62f-6c61c1b50192
/Users/mattzhou/MemGPT/letta/agent.py:251: UserWarning: Tool rules only work reliably for the latest OpenAI models that support structured outputs.
  warnings.warn("Tool rules only work reliably for the latest OpenAI models that support structured outputs.")
Got successful response from client: 

{
    "messages": [
        {
            "id": "message-f79a7a49-b5e6-4f11-a4e5-2a4d0b2add0f",
            "date": "2024-11-07T01:09:41+00:00",
            "message_type": "internal_monologue",
            "internal_monologue": "I should retrieve the first secret word to help find the fourth."
        },
        {
            "id": "message-f79a7a49-b5e6-4f11-a4e5-2a4d0b2add0f",
            "date": "2024-11-07T01:09:41+00:00",
            "message_type": "function_call",
            "function_call": {
                "name": "first_secret_word",
                "arguments": "{\n  \"request_heartbeat\": true\n}",
                "function_call_id": "call_wvQH1XPE7sL0RQyY6S1Rs2pH"
            }
        },
        {
            "id": "message-3e717a69-749b-425f-b6fc-d5c842595115",
            "date": "2024-11-07T01:09:41+00:00",
            "message_type": "function_return",
            "function_return": "{\n  \"status\": \"OK\",\n  \"message\": \"v0iq020i0g\",\n  \"time\": \"2024-11-06 05:09:41 PM PST-0800\"\n}",
            "status": "success",
            "function_call_id": "call_wvQH1XPE7sL0RQyY6S1Rs2pH"
        },
        {
            "id": "message-2554a4cd-b0aa-4aa6-9ea4-e300856dc442",
            "date": "2024-11-07T01:09:43+00:00",
            "message_type": "internal_monologue",
            "internal_monologue": "Now that I have the first secret word, I should retrieve the second one to continue."
        },
        {
            "id": "message-2554a4cd-b0aa-4aa6-9ea4-e300856dc442",
            "date": "2024-11-07T01:09:43+00:00",
            "message_type": "function_call",
            "function_call": {
                "name": "second_secret_word",
                "arguments": "{\n  \"prev_secret_word\": \"v0iq020i0g\",\n  \"request_heartbeat\": true\n}",
                "function_call_id": "call_xCG1m3D4G98AW9WPRKerPkh9"
            }
        },
        {
            "id": "message-7eae72a2-f210-4d45-9f9f-0643e7638df8",
            "date": "2024-11-07T01:09:43+00:00",
            "message_type": "function_return",
            "function_return": "{\n  \"status\": \"OK\",\n  \"message\": \"4rwp2b4gxq\",\n  \"time\": \"2024-11-06 05:09:43 PM PST-0800\"\n}",
            "status": "success",
            "function_call_id": "call_xCG1m3D4G98AW9WPRKerPkh9"
        },
        {
            "id": "message-76e9d6ba-8540-4fb0-a37a-96521cd5f4ff",
            "date": "2024-11-07T01:09:44+00:00",
            "message_type": "internal_monologue",
            "internal_monologue": "I've obtained the second secret word, \"4rwp2b4gxq\". Time to get the third one."
        },
        {
            "id": "message-76e9d6ba-8540-4fb0-a37a-96521cd5f4ff",
            "date": "2024-11-07T01:09:44+00:00",
            "message_type": "function_call",
            "function_call": {
                "name": "third_secret_word",
                "arguments": "{\n  \"prev_secret_word\": \"4rwp2b4gxq\",\n  \"request_heartbeat\": true\n}",
                "function_call_id": "call_dHeodTZYu2TuWjR6fLOuCXrP"
            }
        },
        {
            "id": "message-5f22a9e2-8e36-4a79-9a44-07c3aa8fac3b",
            "date": "2024-11-07T01:09:44+00:00",
            "message_type": "function_return",
            "function_return": "{\n  \"status\": \"OK\",\n  \"message\": \"hj2hwibbqm\",\n  \"time\": \"2024-11-06 05:09:44 PM PST-0800\"\n}",
            "status": "success",
            "function_call_id": "call_dHeodTZYu2TuWjR6fLOuCXrP"
        },
        {
            "id": "message-8302554d-ca0a-47ba-8c15-f8dad0d8d33f",
            "date": "2024-11-07T01:09:45+00:00",
            "message_type": "internal_monologue",
            "internal_monologue": "With the third secret word \"hj2hwibbqm\" in hand, I should now retrieve the fourth."
        },
        {
            "id": "message-8302554d-ca0a-47ba-8c15-f8dad0d8d33f",
            "date": "2024-11-07T01:09:45+00:00",
            "message_type": "function_call",
            "function_call": {
                "name": "fourth_secret_word",
                "arguments": "{\n  \"prev_secret_word\": \"hj2hwibbqm\",\n  \"request_heartbeat\": true\n}",
                "function_call_id": "call_AoLCFuWGjS2WHwxJlU3JVOXy"
            }
        },
        {
            "id": "message-37d9b90f-2158-4357-a62e-c664bb1b6de0",
            "date": "2024-11-07T01:09:45+00:00",
            "message_type": "function_return",
            "function_return": "{\n  \"status\": \"OK\",\n  \"message\": \"banana\",\n  \"time\": \"2024-11-06 05:09:45 PM PST-0800\"\n}",
            "status": "success",
            "function_call_id": "call_AoLCFuWGjS2WHwxJlU3JVOXy"
        },
        {
            "id": "message-14437a25-1579-4970-bb0d-0a6e7afd0f4b",
            "date": "2024-11-07T01:09:46+00:00",
            "message_type": "internal_monologue",
            "internal_monologue": "Now that I've found the fourth secret word, I should tell them the answer."
        },
        {
            "id": "message-14437a25-1579-4970-bb0d-0a6e7afd0f4b",
            "date": "2024-11-07T01:09:46+00:00",
            "message_type": "function_call",
            "function_call": {
                "name": "send_message",
                "arguments": "{\n  \"message\": \"The fourth secret word is \\\"banana\\\". 🍌 Quite an interesting journey through the secrets, isn't it?\"\n}",
                "function_call_id": "call_CB6SdMabWZOFuhOgf8QsNct5"
            }
        },
        {
            "id": "message-b2d343e4-ed66-4d6e-8375-c883b6b40171",
            "date": "2024-11-07T01:09:46+00:00",
            "message_type": "function_return",
            "function_return": "{\n  \"status\": \"OK\",\n  \"message\": \"None\",\n  \"time\": \"2024-11-06 05:09:46 PM PST-0800\"\n}",
            "status": "success",
            "function_call_id": "call_CB6SdMabWZOFuhOgf8QsNct5"
        }
    ],
    "usage": {
        "completion_tokens": 259,
        "prompt_tokens": 10189,
        "total_tokens": 10448,
        "step_count": 5
    }
}
Deleted agent: a407bebb-bd5c-5bcb-8c8d-1416385c76f3 with ID agent-ac772e4d-ebb5-4809-a719-1f84822330c4