Use when ready to implement - selects a GitHub Issue, creates worktree, implements with TDD, verifies, reviews 5x, and creates PR. Numeric argument (e.g. pick-issue 3) is the issue number, not a parallelism count.
Use when you want to be exhaustively questioned about a plan or design until shared understanding is reached - asks one question at a time, traverses the design tree, and proposes a recommended answer for each question
Use to delegate all hands-on work to Codex - plan-writing, implementation, and refactoring. Opus reads, thinks, reviews, and writes docs only.
Use after a PR is opened and you want it merged - waits for CI to pass, marks draft PRs ready, removes the worktree, then merges and cleans up
Use when starting new feature work, adding functionality, or modifying behavior - explores design before implementation, creates plan, PR, and GitHub Issues
Use when encountering test failures, bugs, or unexpected behavior - requires root cause investigation before any fix attempt
Use when creating implementation plans from specs or design documents - decomposes work into concrete TDD tasks with file paths and code examples
Use when writing any implementation code - enforces Red-Green-Refactor cycle with no production code without a failing test first