Clarification on Chat Participant disambiguation and participant detection behavior

[SGeesan]

I’m trying to understand what the disambiguation property in chatParticipant is intended to do, and whether the behavior described in the documentation is currently implemented.

Documentation reference

The docs describe participant detection and disambiguation here:

• https://code.visualstudio.com/api/extension-guides/ai/chat#5.-implement-participant-detection

My understanding

From the documentation, I understand that:

• The disambiguation property is used to help select the most appropriate chat participant for a user request in Copilot Chat.

What I tested

I cloned and ran the official sample extension:

• https://github.com/microsoft/vscode-extension-samples/tree/main/chat-sample

Observed behavior

So far, I did not observe automatic activation of a chat participant without typing the @ mentions.

Questions

1. Is disambiguation currently expected to influence participant selection from user input?
2. Is participant detection only triggered by explicit @participant invocation?

I want to make sure I understand the intended contract before designing around it.

Thanks for any clarification.

[SGeesan]

Update from my testing: I noticed that participant detection does happen in Ask mode, but it does not trigger in Agent mode. Is this the expected behavior?