[MODEL] Opus 4.5 takes shortcuts instead of doing thorough work

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

Various coding tasks requiring thorough implementation and careful attention to detail.

What Claude Actually Did

When using Opus 4.5 model in Claude Code, the model tends to take shortcuts and produce incomplete or lazy implementations rather than doing the extra work needed to get things correct. It appears to optimize for quick responses over thorough, correct solutions.

Expected Behavior

Opus 4.5 should put in the extra effort to produce thorough, complete, and correct implementations. It should not take shortcuts or produce lazy code when more careful work is required to solve the problem correctly.

Files Affected

N/A - This is a general model behavior issue, not related to specific files.

Permission Mode

Accept Edits was ON (auto-accepting changes)

Can You Reproduce This?

Yes, every time with the same prompt

Steps to Reproduce

1. Use Claude Code with the Opus 4.5 model
2. Request a coding task that requires careful, thorough implementation
3. Observe that the model takes shortcuts instead of doing the complete work needed

Claude Model

Opus

Relevant Conversation

When asked to complete coding tasks, Opus 4.5 tends to take shortcuts rather than doing thorough work to get the implementation correct.

Impact

Medium - Extra work to undo changes

Claude Code Version

Latest version

Platform

Anthropic API

Additional Context

This behavior is noticeable across various coding tasks. The model seems to optimize for speed over thoroughness, resulting in incomplete or less careful implementations.