Error: tool_use ids must be unique when doing parallel requests

[bryansusu]

Hi,

I'm getting the following error when using the official Anthropic SDK together with the Microsoft Agent Framework:

{"type":"error","error":{"type":"invalid_request_error","message":"messages.15.content.2: tool_use ids must be unique"}}

This only seems to happen when the agent triggers multiple tool calls in parallel. I don't manually set tool IDs.

Expected: the SDK should either accept parallel tool calls or auto-ensure unique IDs instead of failing.

Could you clarify how tool IDs should be handled, and whether this is a bug or expected behavior?

Thanks!

[1yefuwang1]

I'm facing the same issue using the Microsoft.Extensions.AI.IChatClient interface with streaming enabled if the model returns multiple tool calls.

I did some debugging:
In streaming mode, tool1 is returned first then tool2, then tool3.
The final tool list of this SDK is [tool1, tool1, tool2, tool1, tool2, tool3], where tool1 is duplicated 3 times and tool2 twice.

So, I think the bug is in the IChatClient adaptor which treats the whole streaming response(response1: [too1], response2[tool1, too2], resopnse3[tool1, tool2,tool3]) so far as a delta update, leading to duplicated tool_use messages

[TomerAberbach]

@stephentoub @rogerbarreto is this perhaps a bug in the custom code?

[stephentoub]

@stephentoub @rogerbarreto is this perhaps a bug in the custom code?

Likely. I will look.

[stephentoub]

@bryansusu and/or @1yefuwang1, can you please share a minimal repro demonstrating the issue?

[stephentoub]

Nevermind, I was able to repro. I see the problem. Easy fix.