Use to audit test quality with Google Fellow SRE scrutiny - identifies tautological tests, coverage gaming, weak assertions, missing corner cases. Creates bd epic with tasks for improvements, then runs SRE task refinement on each.
Use when creating or developing anything, before writing code - refines rough ideas into bd epics with immutable requirements
Use when creating Claude Code hooks - covers hook patterns, composition, testing, progressive enhancement from simple to advanced
Use when encountering bugs or test failures - systematic debugging using debuggers, internet research, and agents to find root cause before fixing
Use when facing 3+ independent failures that can be investigated without shared state or dependencies - dispatches multiple agents to investigate and fix independent problems concurrently
Execute entire bd epic autonomously via subagent-per-task dispatch loop. Setup, dispatch subagent per task, end-of-epic review, branch completion.
Use to execute bd tasks iteratively - executes one task, reviews learnings, creates/refines next task, then STOPS for user review before continuing
Use when implementation complete and tests pass - closes bd epic, presents integration options (merge/PR/keep/discard), executes choice