@rm-openai - This addressed the issue we discussed in another thread, would love you review :)

Sorry for delayed review. Was thinking about it, and it feels a bit bad to have tool_call_id be nullable.

What if instead we had ToolContext subclass RunContextWrapper. That way, existing usecases would just work since the downcast is fine. And tool_call_id would be non-null always?

@rm-openai - I added a ToolContext object such that new users will be able to create tool functions that receive the ToolContext instead of the AgentContextWrapper. I also modified the internal FunctionTool class to only receive the ToolContext object in the on_invoke_tool params, so this change will break the type checking of anyone who uses the FunctionTool class directly instead of the wrappers. It seemed reasonable to me, let me know if you think otherwise.