Conciseness

The body is lean and assumes Claude's competence throughout — it never explains what CSS Grid or an HTML document is, and every line is a directive like "thin black hairline + a dateline" or "Background uses a creamy paper tint (`#f3eee2` or DS canvas)". There is no padding or over-explanation; ~56 lines all earn their place, matching the anchor-5 "lean and efficient" example.

Actionability

Guidance is highly concrete with exact values ("text-decoration: line-through; text-decoration-thickness: 2px", "~80px" accent bar, "min-width 1100px", "`data-od-id` on header, headline, deck, each cell, footer") and a copy-paste-ready output contract including the `<artifact>` wrapper. It falls short of anchor 5 only because there is no HTML/CSS skeleton example — the structure must be assembled from prose bullets, a minor gap for a layout-heavy skill.

Workflow Clarity

A clearly sequenced 5-step workflow (read DESIGN.md → pick topic → layout in order → write → self-check) with an explicit self-check checklist of four concrete criteria ("Strikethrough + italic accent both appear, exactly once each", "Looks intentional at 1280–1440px wide"). It misses anchor 5 because the self-check has no feedback loop — nothing says what to do when a check fails (fix and re-verify), and this is a generation task so no destructive/batch cap applies.

Progressive Disclosure

This is a single-file skill with no references/, scripts/, or assets/ directories, and nothing in the body is bulk content that belongs in a separate file — the dense spec is the skill itself. The two sections ("## Workflow", "## Output contract") are well-organized and easy to navigate, which per the rubric's simple-skill guidance earns the top score for a self-contained skill of this size.

Specificity

The description enumerates many concrete, distinctive elements — "oversized serif headline with a struck-through word and italic accent", "a 2-column body block", "6 numbered sections with annotated pull-quote captions" — giving comprehensive coverage of the artifact, but it is framed entirely as a noun-phrase artifact description with no action verbs (no "Produces", "Generates"), so it lists components rather than concrete actions. This sits above anchor 3 (only 1–2 concrete actions) but the absent action framing keeps it below anchor 5.

Completeness

It explicitly answers both questions: the "what" is a detailed description of the editorial poster artifact ("An editorial-style poster — newsprint paper, dateline, oversized serif headline..."), and the "when" is an explicit "Use when the brief asks for..." clause with concrete trigger phrases. This matches the anchor-5 example's structure exactly, and neither half is vague.

Trigger Term Quality

The "Use when" clause lists natural phrases users would actually say — "magazine poster", "editorial poster", "newsprint", "essay layout", "manifesto" — which is good, natural coverage. A few plausible variations are missing from the description itself (e.g. "newspaper", "editorial layout", "poster design"), which keeps it below the comprehensive-with-synonyms anchor 5.

Distinctiveness Conflict Risk

The editorial/newsprint poster niche is distinct and the trigger phrases are unlikely to fire for unrelated skills, but two of the quoted triggers — "essay" and (in the triggers list) "manifesto" — are broad words a user could say when they want prose writing rather than a poster, creating minor overlap risk. Mostly distinct with a small conflict window, which is anchor 4 rather than anchor 5's minimal-conflict bar.