Conciseness

Dense and lean overall — checklists, tables, and complete code with almost no concept explanation Claude already knows. However, the Red Flags section restates ~4 items already covered by the Fast Audit Checklist ("A hero <video> with no poster", "Autoplaying video without muted", "Full YouTube/Vimeo iframes loading at page load", "Multi-MB animated GIFs"), which is trimmable duplication.

Actionability

Copy-paste-ready HTML/CSS for the common cases (hero video with poster/sources/reduced-motion fallback, GIF replacement), exact attribute sets ("muted autoplay loop playsinline", "preload='none'|'metadata'"), concrete numbers ("CRF 21-25", "2-4 rung ladder", "No GIFs over ~500KB"), a thumbnail URL pattern for the facade, and a named component ("lite-youtube-embed") instead of hand-rolling. Specific examples cover the common cases.

Workflow Clarity

The Default Workflow is a clear 5-step sequence ending in an explicit validation step ("Verify with evidence: network waterfall... playback on a throttled mobile profile"), backed by a dedicated Verification section with six concrete checks (e.g., "quality switches under throttling instead of stalling") and a Fast Audit Checklist that routes issues to the Decision Matrix for fixes. This auditing skill is not destructive/batch, so no cap applies.

Progressive Disclosure

Clear overview body with a dedicated "When To Read References" section that signals exactly one level of references — [web-video.md](references/web-video.md) and [sirv-video.md](references/sirv-video.md) — each annotated with its contents; both files exist and contain the promised material, with detail (ffmpeg recipes, HLS setup, SMV options) appropriately kept out of the body. Sibling skills are listed for further navigation.

Specificity

The description lists many concrete covered areas — "Covers MP4/WebM/HLS delivery, H.264/VP9/AV1 codec choice, preload strategies, muted autoplay rules, facades for third-party players, and video-to-spin workflows" — but the lead phrase "Expert guidance on video optimization" is a mildly fluffy framing rather than a concrete action verb, so it sits at 'several specific actions with minor gaps' rather than fully comprehensive.

Completeness

Explicitly answers both parts: what it does ("Covers MP4/WebM/HLS delivery, H.264/VP9/AV1 codec choice, preload strategies...") and when to use it ("Use when adding, auditing, or improving video on websites - hero/background videos... GIF-to-video conversion..."). Concrete trigger phrases attach to the 'Use when' clause, matching the top anchor.

Trigger Term Quality

Comprehensive natural trigger phrases users would actually say: "hero/background videos", "product demo videos", "autoplay loops", "GIF-to-video conversion", "video posters and thumbnails", "lazy loading video", "YouTube/Vimeo embed performance", "video Core Web Vitals (LCP/CLS/INP)", plus technical terms (MP4/WebM/HLS, H.264/VP9/AV1) and host names. Matches the comprehensive-synonyms anchor.

Distinctiveness Conflict Risk

Clear web-video niche with distinct triggers, but "video posters and thumbnails" and "video-to-spin workflows" overlap with closely related sibling skills (image-optimization, sirv-360-spin), and "video SEO/schema" could pull generic SEO requests. Mostly distinct with minor overlap risk — fits the 4 anchor better than the minimal-conflict 5 anchor.