Fixed the OpenAI compatible tools format to send function nested object in the tools array instead of putting function properties at the top-level.
This resolves the 400 Bad Request Field required validation error for models connecting via OpenRouter/OpenAI API like qwen/qwen3.5-122b-a10b.
Also removed strict: false parameter to maximize compatibility with third-party models since many models strictly validate the JSON schema but don't recognize the strict field itself.