For instance, this code would be invalid: Python type-checking systems will ... can automatically infer what types are returned from a function. But if you plan on using type hinting with a ...

Hello, I run a simple test for function tools calling with gpt-4o. However, I met a bug "Invalid parameter: messages with role 'tool' must be a response to a preceeding message with 'tool_calls'. " .

Introduction Modern applications are increasingly powered by large language models (LLMs) that don’t just generate text—they can call live APIs, query databases, and even trigger automated workflows.