Parallel Implementation

Planner skill — returns a slice plan, does not invoke subagents itself. The main Agent keeps execution authority.

When to Use

Invoke only when one of these triggers fires:

1. Greenfield 0→1 across multiple independent modules → plan a layered parallel split (e.g., data / service / UI layers each as their own slice). Greenfield independence makes this the cleanest parallel case.
2. Change touches ≥3 modules → the main Agent should confirm with the user via AskUserQuestion whether to parallelize; some cross-module edits are better serialized.
3. Change touches ≥5 files AND each file's diff exceeds 50 lines → the total work justifies dispatch overhead; recommend parallel.
4. User explicitly asks for "parallel write", "多 agent 并行实现", or "split this across subagents" → honor regardless of size.

Don't use for:

• Single-file, 2-file, or 3–4 file changes where any slice's diff is <50 lines → main Agent writes it inline
• Refactors where all callers cascade from a single change (e.g., renaming a widely-used helper) → serialize through main Agent
• Work with serial dependencies (B needs A's output) → that's a pipeline, not parallel
• Pure read tasks (review, search, analysis) → parallel subagents without slicing are fine; no planning needed