Use when approach is chosen and need a detailed implementation plan before coding. After researching, before implementer
Use when idea is vague, multiple interpretations exist, scope is undefined, or stakeholders need alignment before technical work begins
Use when requirements are fuzzy, multiple technical approaches exist, or change affects architecture, API, data, or security
Use when an approved implementation blueprint exists and you are about to start implementation
Use when code needs behavior-preserving restructuring to improve clarity, reduce duplication, or enable safer changes without altering outputs
Use when need to create reusable technique, pattern, or reference guide for AI agents
Use when need to create specialized subagent for recurring tasks, domain-specific work, or pipeline automation