A Foundry agent with several function tools returns two function_call items in one…

How it works

With function tools, your app runs the code: the agent returns function_call items, your app executes them, and you send the outputs back so the agent can continue. When the model decides it needs several functions in one response, the function calling page's troubleshooting guidance is:

1. Handle each function call in the output array.
2. Return all results in a single responses.create call.

This app runs only the first call and replies, so the agent is missing the second result and can't finish correctly. Also keep an eye on timing: runs expire 10 minutes after creation, so submit tool outputs before then.

Testing has a related limit. The same troubleshooting table says the portal doesn't execute function calls: it shows agents but doesn't invoke functions, so test function calling with the SDK or REST API. The portal also doesn't support adding, removing or updating function definitions.

The other options, and when you'd use them

• tool_choice none: The model then doesn't call tools at all. That doesn't make it call one function at a time.
• One responses.create per result: The guidance is all results in a single responses.create call.
• Test in the portal: The portal doesn't execute function calls. Test with the SDK or REST API.

Exam tip

Multiple function_call items = run them all, then return every output in one responses.create call.

References

• Use function calling with Microsoft Foundry agents
• Tool best practices for Microsoft Foundry Agent Service