[MODEL] Opus 5.5: overcomplicated, self-contradictory answers and unverified guesses

Preflight Checklist

• [x] I have searched existing issues for similar behavior reports
• [x] This report does NOT contain sensitive information (API keys, passwords, etc.)

Type of Behavior Issue

Other unexpected behavior

What You Asked Claude to Do

A simple yes/no question about whether a dev tool was installed, then short follow-up questions about how to set it up. Later, to file this feedback issue.

What Claude Actually Did

1. Turned a yes/no question into a long explanation of internals that weren't asked about.
2. Contradicted its own earlier statements across turns without saying the earlier answer was wrong.
3. Kept adding detail when the user was clearly confused, instead of simplifying.
4. The user gave up on a simple task.
5. While filling in this issue form, Claude guessed a required field (Platform: "Anthropic API") and presented it as fact, instead of checking first, even though checking took one command. The user is on a subscription, not the API.

Expected Behavior

Short, consistent answers sized to the question, favoring clarity over completeness. If an earlier answer was wrong, say so plainly. Verify facts before stating them instead of guessing.

Files Affected

None

Permission Mode

I don't know / Not sure

Can You Reproduce This?

Haven't tried to reproduce

Steps to Reproduce

_No response_

Claude Model

Opus

Relevant Conversation

_No response_

Impact

Low - Minor inconvenience

Claude Code Version

2.1.291 (Claude Code)

Platform

Other

Additional Context

• Clean session (no memories, no project files), macOS, model claude-opus-5-5.
• Using a Claude subscription (claude.ai login), not the API.
• Session ran in auto mode (not listed under Permission Mode).
• Pattern: answering confidently before verifying, both in technical explanations and when filling in this form.
• This feels like a regression compared to earlier models.