Internal error: classifyHandoffIfNeeded is not defined

Bug Description

When using the Task tool to spawn subagents (general-purpose type), the agents complete their work successfully but then fail at the end with an internal error:

classifyHandoffIfNeeded is not defined

Steps to Reproduce

1. Use the Task tool to launch a general-purpose subagent
2. Have the agent perform file edits using the Edit tool
3. Agent completes all edits successfully
4. Agent fails with the error after completing work

Environment

• Claude Code version: 2.1.29
• Platform: Windows 11
• Model: claude-opus-4-5-20251101

Expected Behavior

The agent should complete successfully after finishing its work.

Actual Behavior

The agent completes all requested work (edits are applied and verified), but then throws an internal error:

classifyHandoffIfNeeded is not defined

The task status shows as "failed" even though all work was completed.

Impact

Low - the work is completed successfully, but the error causes confusion as the task shows as "failed" despite success. Users may unnecessarily retry completed work.

Additional Context

This occurred when running two parallel agents to apply code review fixes to planning documents. Both agents experienced the same error after successfully completing their edits.

Task output files showing the error:

• Agent a13708c: Completed Phase 3 fixes, then failed
• Agent adb5b4f: Completed Phase 4 fixes, then failed

The error appears to be in the agent handoff/completion logic rather than in the actual task execution.