[BUG] AskUserQuestion in plan mode doesn't render questions — auto-submits empty answers

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?

<img width="978" height="534" alt="Image" src="https://github.com/user-attachments/assets/542c62a8-f1b9-4c5c-9da6-24a73e15c77c" />

What's Wrong?
When Claude uses AskUserQuestion during plan mode, the question UI never renders.
Instead, the tool auto-completes immediately with empty/blank answers. Claude then sees
the empty response, says "your selections didn't come through clearly," and asks again
— creating an infinite loop where the user never gets to see or answer the questions.

The conversation shows repeated "User answered Claude's questions:" entries with blank
answers (just └) even though the user never saw any question UI.

What Should Happen?

The AskUserQuestion UI should render the questions and options, allow the user to make
selections, and return those selections back to the model. This works correctly outside
of plan mode.

Error Messages/Logs

Error Messages/Logs
  No error output — the failure is silent. The question tool auto-completes with empty
  answers without displaying anything to the user.

Steps to Reproduce

Steps to Reproduce

1. Enter plan mode (/plan or via EnterPlanMode)
2. Give Claude a task that requires clarifying questions (e.g., a design/implementation

task with multiple valid approaches)

1. Claude calls AskUserQuestion with multiple options
2. Question UI never appears — "User answered Claude's questions:" shows immediately

with blank answers

1. Claude sees empty responses, says selections "didn't come through clearly," and

loops

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.63

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_