fix: handle additionalProperties in json_schema_to_pydantic_type

[hashwnath]

Summary

Fixes #3087

When a JSON schema defines an object with additionalProperties but no explicit properties (e.g. {"type": "object", "additionalProperties": {"type": "string"}}), json_schema_to_pydantic_type() delegates to create_model_from_schema() which generates an empty Pydantic model. This causes Pydantic to silently strip all fields during validation, resulting in empty objects like [{}] instead of the expected data.

This affects any tool in the catalog whose schema uses additionalProperties without explicit properties — including OUTLOOK_CALENDAR_CREATE_EVENT's attendees_info field.

Fix

Before delegating to create_model_from_schema(), check if the object schema has additionalProperties but no properties. In that case, map directly to Dict[str, value_type]:

Schema	Before	After
{"type": "object", "additionalProperties": {"type": "string"}}	Empty model → {}	Dict[str, str]
{"type": "object", "additionalProperties": {"type": "integer"}}	Empty model → {}	Dict[str, int]
{"type": "object", "additionalProperties": true}	Empty model → {}	Dict[str, Any]
{"type": "object", "properties": {...}}	Unchanged	Unchanged

Verification

Using the MRE from the issue:

from composio.utils.shared import json_schema_to_model

schema = {
    "type": "object",
    "title": "CreateEventRequest",
    "properties": {
        "attendees_info": {
            "type": "array",
            "items": {
                "type": "object",
                "additionalProperties": {"type": "string"}
            },
            "default": []
        }
    }
}

Model = json_schema_to_model(schema)
result = Model.model_validate({
    "attendees_info": [
        {"name": "John Doe", "type": "required", "email": "john@example.com"}
    ]
})
print(result.model_dump())
# Before: {'attendees_info': [{}]}
# After:  {'attendees_info': [{'name': 'John Doe', 'type': 'required', 'email': 'john@example.com'}]}

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