[BUG] using /btw would sometime result in No response received

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

/btw would return "No response received"
With extended thinking, the model would return an empty text block then a thinking block and then the real text block after. The empty text block is probably causing the No response received.

What Should Happen?

Return a response

Error Messages/Logs

No response received

Steps to Reproduce

1. Start a new interactive session
2. Ask it to read @{some local file}
3. /btw yes (before it uses the tool)
4. /btw would return "No response received"

Claude Model

Opus

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

2.1.73

Platform

Google Vertex AI

Operating System

Ubuntu/Debian Linux

Terminal/Shell

IntelliJ IDEA terminal

Additional Information

_No response_