{"model": "gpt-5.4", "max_tokens": 128, "messages": [{"role": "user", "content": "reply with exactly OK"}], "tools": [{"name": "Read", "description": "Reads a file from the local filesystem.", "input_schema": {"type": "object", "properties": {"file_path": {"type": "string"}}, "required": ["file_path"], "additionalProperties": false}}]}