ExitPlanMode response message misleadingly implies plan approval

Summary

The ExitPlanMode tool returns the message:

User has approved exiting plan mode. You can now proceed.

This reads as "the user approved your plan, go ahead and implement". In practice, ExitPlanMode only presents the plan to the user for review — it does not constitute approval. The phrase "You can now proceed" is the main culprit.

Observed behaviour

1. Claude writes a plan to the plan file
2. Claude calls ExitPlanMode
3. The tool response says "User has approved exiting plan mode. You can now proceed."
4. Claude interprets this as plan approval and begins implementation immediately
5. The user hasn't actually reviewed or approved the plan

Expected behaviour

The tool response should clearly indicate that the plan has been presented for review and that Claude must wait for explicit user feedback before implementing. Something like:

Plan presented to user for review. Wait for explicit user approval before implementing.

Workaround

Added this to our project CLAUDE.md:

ExitPlanMode approval is NOT plan approval — it only means the user has agreed to see the plan. ALWAYS wait for explicit user confirmation before implementing.