Use ONLY for an independent full-scope audit of a canonical implementation plan or an implementation diff. Treat builder summaries and transcripts as untrusted, reconstruct the relevant behavior from the repository, require evidence for every blocking finding, and never narrow scope after revisions.
Use ONLY when the user asks to implement a canonical plan whose current revision has a recorded full-scope approval. Execute only the approved revision, load the TDD skill, implement the approved primary-path repair or exact user-requested rollback without adding fallback behavior, verify the complete requirement, and require a full independent implementation audit before declaring completion.
Use ONLY when the user asks for an implementation plan, design proposal, root-cause repair plan, or when the approved-plan workflow requires a fresh canonical plan. Research the current repository from scratch, write or revise the versioned canonical plan, and do not modify production code.