stopbug-guard

name	stopbug-guard
description	Discipline for preventing the stop bug (malformed tool call -> self-priming). Fires when the stopbug-observe hook emits a trip-wire (migration advice) or the time-based timer (calibration prompt), or as a minimal focus-check right before heavy processing.

stopbug-guard — stop-bug prevention discipline

When it fires

• When the stopbug-observe Stop hook emits a migration advice (a malformed output was observed in this session).
• When the Stop hook emits a calibration prompt (observation data reached the collection period).
• As a minimal focus-check right before heavy processing (multi-file edits, long generation).

Rationale (why)

A malformed tool call stays in the history as an "example" and pulls subsequent output toward repeating it (self-priming). The true root fix — constrained decoding at the serving layer — is only available on the Anthropic side. At this layer the strongest and cheapest lever is to cut the polluted context early = migrate the session. The reminder is only a weak auxiliary. Machine observation is done by the hook, the recovery discipline by [[priming-loop-recovery]], and the migration path by [[cc-state-declaration]]. This skill only holds the steps that connect them.

Procedure A — on a migration advice (trip-wire)

1. This is a safe stopping point. Do not start additional heavy work.
2. Write a clean handoff note (purpose / done / next action only).
   • Never quote the malformed output (avoid re-priming).
3. Exit with /exit and resume with claude --resume <session-id> ([[cc-state-declaration]]).
   • A fresh session is the most reliable. /clear plus the handoff note also works.
4. After migrating, resume work from the handoff note.

Procedure B — on a calibration prompt (time-based timer)

1. Outside the conversation, run python ~/.claude/hooks/stopbug-calibrate.py.
2. Check the malformed base rate and the conditional rate (chance of more malformed after the first).
3. If enabling the trip-wire (Phase 2) is warranted, set TRIPWIRE_ENABLED to true in ~/.ccpit/.stopbug-config.json (no settings change needed, only the config file).

Procedure C — right before heavy processing (minimal, weak auxiliary)

• Tighten focus in one line: "emit tool calls now in the correct format, one at a time."
• Do not lecture yourself further (do not bloat context). The real lever is migration in Procedure A.

Prohibited

• Do not reproduce tool-call syntax (invoke / parameter / function_calls) in hook reasons or notes.
• Do not add a fancy predictor "to be smarter." The lever is migration.

References

• [[priming-loop-recovery]] — recovery protocol for consecutive malformed output (the parent discipline).
• [[cc-state-declaration]] — self-restart / migration path at a safe stopping point.
• Observation core: ~/.claude/hooks/stopbug-observe.py, calibration: stopbug-calibrate.py.