Claude Opus 5.5: no progress/intent text shown between tool calls

[alexginis]

Describe the bug

When using Claude Opus 5.5, the short progress/intent text the model writes before or between tool calls is not shown during the model turn. The UI stays silent until the final answer.

With Claude Opus 5 and GPT models, a short line describing what the model is about to do appears while it works, so this is a regression when switching to Opus 5.5.

This matches a documented behavior change in Claude Opus 5.5: text between tool calls now comes back as progress-update thinking blocks instead of text blocks, and their text is empty at the default display: "omitted" setting. Applications that stream this text to users "go quiet between tool calls, with no error" until they set a display value that returns the text.

• https://platform.claude.com/docs/en/models/opus-5-5/whats-new-opus-5-5 (see "Text between tool calls comes back in thinking blocks")
• https://platform.claude.com/docs/en/models/opus-5-5/migration-guide#text-between-tool-calls

Affected version

GitHub Copilot CLI 1.0.88 (runtime used by the GitHub Copilot desktop app 1.1.23)

Steps to reproduce the behavior

1. Open a chat/session in the GitHub Copilot app and select Claude Opus 5.5.
2. Ask for a task that requires several tool calls (e.g. "inspect the files in this folder and summarize them").
3. Observe that no progress/intent text is shown between tool calls.
4. Switch the model to Claude Opus 5 or a GPT model and repeat: the progress text is shown.

Expected behavior

Progress/intent text is shown for Claude Opus 5.5 as it is for other models, e.g. by requesting a thinking display setting that returns progress updates and rendering those progress-update thinking blocks in the UI.

Additional context

• OS: Windows 11 (10.0.26200), x64
• Observed in the GitHub Copilot desktop app; filed here because the model integration runs in the Copilot CLI runtime.

[alexginis]

Update: this looks fixed in 1.0.89. The release notes include "Adding support for claude-opus-5.5".

I ran the same multi-step task with --model claude-opus-5.5 --reasoning-effort high on both versions and compared the assistant.message events:

Version	Intermediate turns with progress text in content
1.0.87-0	0 of 5 (the text appeared only in reasoningText)
1.0.89	3 of 4 (e.g. "Python isn't installed, so I'm using Node for the second check.")

In 1.0.89 the thinking summary and the progress text arrive separately, so the progress text can be shown to the user. I ran it once per version, so the counts are indicative.

The desktop app doesn't have the fix yet. It starts its bundled CLI with --no-auto-update, which loads the 1.0.87-0 package, so the app should pick this up once it ships a newer runtime.

Closing as fixed in 1.0.89.