fix: use Optional[str] instead of str | None for Google ADK function parameters

[jonigl]

Fix Google ADK Python Sample

Summary

Fixed automatic function calling errors in the Google ADK agent by replacing str | None type hints with Optional[str] in function signatures. This makes the function signatures compatible with automatic function calling parsers.

The error

This error happens when trying to use the google adk agent from the python samples https://github.com/google/A2A/tree/main/samples/python/agents/google_adk .

When requesting a reimbursement in a conversation the agent tries to handle the form but it fails throwing the following error:

ERROR:task_manager:An error occurred while streaming the response: Failed to parse the parameter date: str | None = None of function create_request_form for automatic function calling. Automatic function calling works best with simpler function signature schema,consider manually parse your function declaration for function create_request_form.

• Also check the screenshots below.

Changes

• Updated type annotations in create_request_form function
• Updated type annotations in return_form function
• Added proper import of Optional from typing module

Testing

Verified that the agent now properly handles function calls without parsing errors.

Some screenshots

• Running agent and demo ui
  
• Adding the agent
  
• Requesting a reimbursement makes agent to fail
  
• Here it is the error
  

ERROR:task_manager:An error occurred while streaming the response: Failed to parse the parameter date: str | None = None of function create_request_form for automatic function calling. Automatic function calling works best with simpler function signature schema,consider manually parse your function declaration for function create_request_form.

• Once applying the fix it is working as expected
  
• Form is shown and correctly handled by the agent
  

---

Description

Thank you for opening a Pull Request!
Before submitting your PR, there are a few things you can do to make sure it goes smoothly:

• Follow the CONTRIBUTING Guide.
• Make your Pull Request title in the https://www.conventionalcommits.org/ specification.
• Ensure the tests and linter pass (Run nox -s format from the repository root to format)
• Appropriate docs were updated (if necessary)

Fixes #457 , #422 🦕

[jonigl]

this was fixed some hours ago by this PR #510 thanks @swapydapy 🙌

[jonigl]

closing this PR now