The body is lean and assumes Claude's competence, never explaining what a plan is, with every line actionable ('Ask at most 1–2 questions', 'default 6–10 items'), matching the score-3 'every token earns its place' anchor rather than the padded score-1/2 examples.

It gives concrete, copy-paste-ready guidance — a literal plan template, specific targets (README.md, docs/, CONTRIBUTING.md), verb-first phrasing, and validation cues ('Run npm test', 'feature flag, migration plan, rollback note'); absence of code is not penalized for an instruction-only skill since the guidance is actionable, so it is not the incomplete score-2 or vague score-1 case.

A clearly sequenced 4-step Minimal workflow plus a checklist template provides explicit ordering; the destructive/batch-operation validation cap does not apply because the skill mandates read-only mode ('Do not write or update files'), placing it at score 3 rather than the implicit-checkpoint score-2 case.

The skill is self-contained with no bundle files and is organized into clear sections (Goal, Minimal workflow, Plan template, Checklist item guidance); per the simple-skill guidance, well-organized self-contained content without nested references scores 3, not the monolithic score-1 or split-needed score-2 cases.

It names the domain and a concrete action ('Create a concise plan') but lists only a single action rather than multiple specific concrete actions, matching the 'Names domain and some actions, but not comprehensive' anchor and not the score-3 multi-action examples or the score-1 vague cases.

It explicitly answers both what ('Create a concise plan') and when ('Use when a user explicitly asks for a plan related to a coding task') with an explicit 'Use when' trigger, matching the score-3 anchor rather than score 2 where the 'when' is only implied.

It includes a natural, commonly-said trigger ('asks for a plan') but coverage is narrow — only 'plan' is covered, missing variations like 'roadmap', 'breakdown', or 'steps' — so it falls short of good coverage at score 3 while staying above the score-1 jargon-only bar.

The trigger 'explicitly asks for a plan related to a coding task' carves a clear, narrow niche unlikely to fire for unrelated skills, matching the score-3 anchor; the coding-task qualifier distinguishes it from generic planning skills rather than the overlapping score-2 case.