[BUG]

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?

Claude repeats the same explanation 3-4 times in a single response when using agent research results combined with its own summary

What Should Happen?

When Claude uses an agent to research something and then summarizes the result, it should give you one clean explanation — not repeat the same point in its own intro, then in the agent output, then again in its closing summary.

Error Messages/Logs

Steps to Reproduce

1. Ask Claude a conceptual question
2. Tell it to "use an agent to research this"
3. Claude will write its own intro, then paste the agent's full output, then write its own summary — all three sections will say the same thing in

different words

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

v2.1.143.

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Cursor

Additional Information

<img width="1099" height="629" alt="Image" src="https://github.com/user-attachments/assets/f58894f6-8efc-488e-9abb-1271664c776f" />