Tool Input Array JSON Schema Validation problems #410

Describe the bug

Open AI's implementation of schema validation cannot tolerate optional array arguments

• fix: add required fields for OpenAI API github/github-mcp-server#39
• fix: update json schema for create_pull_request_review github/github-mcp-server#300

Windsurf required a different interpretation

• fix: use anyOf instead of nullable type array github/github-mcp-server#325

Gemini seems to also have validation issues

[{
  "error": {
    "code": 400,
    "message": "Unable to submit request because `create_pull_request_review` functionDeclaration `parameters.comments.side` schema didn't specify the schema type field. Learn more: https://cloud.google.com/vertex-ai/generative-ai/docs/multimodal/function-calling",
    "status": "INVALID_ARGUMENT"
  }
}
]

To Reproduce

1. Install the GitHub MCP Server
2. Attempt to call create_pull_request_review with different models

Expected behavior
Specification drives a consistent behaviour across all model providers when receiving a valid tool input schema