Plan mode: ExitPlanMode tool not available via ToolSearch, incomplete tool access

Problem

When entering Plan Mode, the ExitPlanMode tool is referenced in the system prompt instructions but is not available through ToolSearch. The plan mode instructions say:

"At the very end of your turn, once you have asked the user questions and are happy with your final plan file - you should always call ExitPlanMode"

But ToolSearch returns "No matching deferred tools found" for both select:ExitPlanMode and keyword search "exit plan".

Environment

• Claude Code on Windows 11
• Model: Opus 4.6 (1M context)
• Date: 2026-04-07

Steps to Reproduce

1. Enter plan mode (e.g., user approves a plan)
2. Complete planning and write plan file
3. Attempt to call ExitPlanMode via ToolSearch
4. Tool not found — plan mode cannot be properly exited programmatically

Expected Behavior

ExitPlanMode should be discoverable via ToolSearch and callable like other deferred tools.

Workaround

User manually exits plan mode via the /plan command.