Phase 2 — Plan

Turn the approved analysis into an executable plan. The quality bar: an implementer-tier model must be able to execute each task without asking questions.

Pin the spec

Write the spec down before delegating anything. It contains:

• The decided approach — including decisions already made, so the implementer does not relitigate them.
• Files to touch, and the entry points to start from.
• Constraints: style rules, patterns to follow (point at existing code), performance or compatibility requirements.
• The language, framework, and format skills covering the files this task touches. Load them in this phase, before any code is written, and copy the rules that bind this task into the spec — control flow, test structure, logging, comment style. A skill loaded at verification does not prevent violations, it converts them into rework.
• When the change replaces working code (rewrite, port, engine swap, dependency change), enumerate what the replaced code currently does by reading that code, not the request, and make that list the acceptance criteria. Keybindings, auto-inserts, defaults, and error messages all count. Anything on the list you intend to drop is a removal that needs the user's go before you write the replacement — never a simplification you report afterward.
• Sample data, demo fixtures, and shipped defaults must be generic. Never promote a real person's, client's, or the user's own data to the default state of the project, even when the source material came from them — carry it as a private example instead.
• Verification commands the implementer must run locally (build, tests, lint).
• Explicit non-goals: what the task must NOT change. This is what keeps subagents from wandering.

Split into tasks

• One task = one self-contained unit an implementer can finish and verify on its own.
• Mark which tasks are independent and which consume another task's output. Parallelize the independent ones; sequence the rest. When in doubt, sequence — a merge conflict between two parallel subagents costs more than the parallelism saves.
• Documentation updates belong to the task that changes the behavior, not to a separate task.

Decide the workspace per task

• Main working tree: when the task depends on uncommitted local changes, or when you will review and commit the result in the current session.
• Isolated worktree: everything else, especially parallel tasks — they must never share a working tree.

Output of this phase

A task list where each entry names its executor tier (see Phase 3), its workspace, its dependencies, and carries its pinned spec.