Use when a user message needs Chinese-first intent inference, low-confidence collaborative clarification, routing, workflow weight control, skill choice, review/testing/planning/debugging/evaluation routing, proactive multi-thread collaboration or conflict coordination, continuation handling, execution permission inference, or protection from process over-escalation.
Use when active development or explicit refactoring has concrete code-structure risk: a source file is accumulating independently changing responsibilities, a class/component/function is hard to navigate or test, repeated changes touch distant sections, or the user asks to split a giant file; do not use for line count alone, generated/vendor/migration/schema/fixture files, or cohesive modules that remain easier to maintain together.
Use when the user explicitly enables an automated same-project multi-thread development loop that keeps peer Codex tasks progressing, recovers conflicts or stale coordination, integrates verified work into local main, and closes cleanup without repeated gates; do not use before opt-in, for one-off coordination, remote publication without permission, or subagent creation.
Use when existing independent Codex App threads work in the same project and need peer advice, collaboration proposals, shared progress awareness, ownership arbitration, conflict pause/resume, discussion, merge coordination, status exchange, or handoff through native thread tools without creating subagents.
Use when a verified or integrated software change has concrete temporary artifacts, generated noise, stale claims, merged local branches, or disposable worktrees to clean, or when the user explicitly asks to remove development residue or old branches.
Use when the user or project rules explicitly request project-local memory/dashboard initialization or updates, or when an existing `.docs/project-memory/` is needed for cross-session recovery, durable decisions, blockers, parallel-agent coordination, or formal handoff; do not auto-initialize or sync it for ordinary development.
Use when two or more existing, independent Codex App threads in the same project can help each other finish their own tasks through peer negotiation, shared-contract alignment, dependency exchange, conflict reduction, or coordinated local integration; do not use to create or command subagents, transfer ownership, or add ceremony to unrelated work.
Use when an explicit performance goal, measurable regression, unresolved hot path, large workload, concurrency/cache/streaming decision, or latency/throughput/CPU/memory/I/O/bundle budget needs profiling and evidence-backed optimization; do not use for routine development, speculative cleanup, or an already-located N+1/local inefficiency whose batch fix and deterministic count verification are clear to the current owner.