Skill: planning-spec

Purpose

Left to default behavior, an agent jumps straight from a request to a task list and starts editing. That fails in three quiet ways: it plans in a vacuum (ignoring how this project is already built), it never states what it won't do (so scope drifts as the work proceeds), and it commits to an approach no human ever approved (so a wrong direction is discovered only after the work has multiplied into a dozen edits).

This skill inserts a planning stage with three checkpoints the default skips: check the approach against the project's durable principles, write the out-of-scope line, and stop for a human "go" before the plan becomes a task breakdown. The leverage is timing — a plan is a paragraph you can rewrite in seconds; a fanned-out breakdown with half the edits done is expensive to unwind.

When a plan is worth it

Plan when the change is open-ended or spans more than one file/module/step. Skip the ceremony for a one-line fix, a lookup, or a change whose shape is already pinned down — a plan that only restates an obvious task list is pure overhead (see Gotchas).