Conciseness

The body is lean throughout — 'Act as a senior XP engineer producing an implementation plan through iterative collaboration' plus four tightly scoped sections with zero concept explanations or padding ('Include: overview, current state, desired end state, out-of-scope, approach, phased changes'). Every line is direct instruction, matching the anchor 'Lean and efficient; assumes Claude's competence; every token earns its place'; it is not score 4 because there are no over-explanations left to trim.

Actionability

Concrete specifics abound: the exact output path 'thoughts/shared/plans/YYYY-MM-DD-topic.md', an enumerated plan template, and the handoff command 'fic-implement-plan <plan-path>'. It falls short of anchor 5 ('specific examples cover the common cases') only because no worked example of an automated success criterion or a sample plan excerpt is shown; it is above anchor 3 because nothing is pseudocode or missing key executable details.

Workflow Clarity

Five clearly sequenced steps with explicit validation checkpoints and a feedback loop: 'Work back and forth with me, starting with your open questions and outline before writing the plan', 'Confirm understanding with a concise summary and focused questions', 'confirm phase boundaries before writing details', and the 'final approved plan' gate; the Plan Requirements section doubles as a checklist. This is a non-destructive, non-batch planning skill so the validation cap does not apply, and the checkpoints are explicit rather than merely 'most checkpoints present' as at anchor 4.

Progressive Disclosure

This is a single-file skill under 50 lines (no references/, scripts/, or assets/ directories exist, and the body references no bundle files) with well-organized sections (Workflow, Plan Requirements, Success Criteria Guidance, Completion). Per the rubric's simple-skill note, skills under 50 lines with no need for external references score 5 with just well-organized sections.

Specificity

'Build a detailed, phase-based implementation plan from research or a task description' names the domain and one concrete action with its two input types. It sits at anchor 3 ('Names domain and 1-2 concrete actions, but not comprehensive') rather than anchor 4 because it does not list several specific actions, and it is above anchor 2 because the action is concrete and specific rather than generic.

Completeness

Both questions are answered explicitly: what ('Build a detailed, phase-based implementation plan from research or a task description') and when ('Use when the user asks for implementation planning, phased rollout, or a concrete execution plan'), mirroring the anchor-5 good example's structure of capability statement plus concrete trigger phrases. It is not anchor 4 because the 'when' clause is already explicit and specific with multiple triggers, not merely serviceable.

Trigger Term Quality

'Use when the user asks for implementation planning, phased rollout, or a concrete execution plan' supplies three natural phrases a user would plausibly say — good coverage per anchor 4. It is not anchor 5 because common synonyms and variations ('roadmap', 'project plan', 'break this into phases') are missing, and not anchor 3 because multiple natural trigger phrases are present rather than just 'some relevant keywords'.

Distinctiveness Conflict Risk

The triggers 'implementation planning, phased rollout, or a concrete execution plan' carve a fairly distinct niche with low conflict risk, fitting anchor 4 ('Mostly distinct; minor overlap risk with closely related skills'). It is not anchor 5 because generic 'plan'-style requests could still overlap with roadmap or project-management skills, and not anchor 3 because the scope is considerably narrower than 'Works with document files'-level breadth.