Rates confidence that the current work fully solves the stated requirement. Supports plan validation, code review, and analysis (root-cause, refactor, diagnose) modes. Plan mode combines LLM judgment with deterministic rule checks (multi-signal gate); a failed rule caps the gate at 89% regardless of LLM score. Use before committing to autonomous execution, after implementation, or during investigation. Triggers on "confidence check", "validate plan", "rate confidence", "quality gate", "/confidence".