Conciseness

The body is lean and assumes competence: no explanation of HTML/CSS or what a carousel is; every line is instruction or concrete spec ('1080×1080 cinematic still', 'radial-gradient + linear-gradient only — no images', 'stack at < 1100px'). Matches anchor 5 — every token earns its place; not 4 because there is no over-explanation to trim.

Actionability

Fully executable guidance: exact CSS values ('aspect-ratio: 1 / 1', 'width: clamp(280px, 30vw, 380px)', 'rounded 12px corners', '1px border'), per-panel gradient recipes, required data attributes ('data-od-id on stage, each card, each headline'), and a copy-paste output contract template with the artifact wrapper. Matches anchor 5; not 4 because the common case (a 3-card carousel) is completely specified end to end.

Workflow Clarity

Six clearly sequenced steps (read DESIGN.md → pick theme/captions → stage → cards → write → self-check) ending in an explicit 3-point self-check checklist ('The three headlines together form one sentence...', 'no two share a dominant hue'). For this simple, non-destructive single-task skill this matches anchor 5; not 4 because the validation step is explicit and criterion-based, not merely implied.

Progressive Disclosure

The skill is a self-contained ~60-line single-task document with no references/, scripts/, or assets/ bundle and no external file pointers; content is well-organized under clear sections (Workflow, Output contract). Per the simple-skill guidance, this matches anchor 5 — nothing that belongs in a separate file is inlined.

Specificity

The description enumerates several concrete, checkable artifact details — '1080×1080 squares', 'display headlines that connect across the series', 'brand mark, a number / total, a caption, and a "loop" affordance' — but frames them as one deliverable rather than listing multiple distinct actions, matching anchor 4 ('several specific actions; minor gaps') rather than 5's 'multiple specific concrete actions'.

Completeness

It explicitly answers both questions: the 'what' is concrete ('three cinematic, on-brand panels' with enumerated card elements at a fixed size) and the 'when' is an explicit 'Use when the brief asks for a...' clause with concrete trigger phrases, exactly matching anchor 5. Not 4 because the 'when' clause is not merely present but specific and multi-phrase.

Trigger Term Quality

'Use when the brief asks for a "carousel post", "social carousel", "Instagram carousel", "LinkedIn series", "X thread cards", or "三连发"' gives good natural, platform-specific coverage including a Chinese synonym, but misses common variants like 'social media carousel', 'multi-image post', or 'thread images', fitting anchor 4 ('good keyword coverage; a few natural terms missing').

Distinctiveness Conflict Risk

A clear niche (social-media carousel design, fixed at 'three-card' and '1080×1080') with distinct triggers ('Instagram carousel', 'X thread cards') that would not fire for general design or other format skills — minimal conflict risk, matching anchor 5.