Conciseness

The body is composed of terse, viewer-specific imperatives Claude would not know on its own ('Do not call fetch, XMLHttpRequest, WebSocket', 'Images must be data: URIs'), but the 'Authoring contract' and 'Web design requirements' sections duplicate each other — responsive layout/no horizontal overflow, prefers-reduced-motion, accessible labels, and native controls each appear twice. It sits above the 'mostly efficient' anchor but the repeated bullets keep it from 'every token earns its place'.

Actionability

Guidance is concrete and executable — exact tool invocations with kwargs ('Call verify_artifact(path=output_path, format="html")', 'save_artifact(path=output_path, title="...", markdown_representation="...")', 'load_artifact_for_revision'), named prohibited APIs, and explicit allowed hosts (fonts.googleapis.com, fonts.gstatic.com). Minor gaps remain: placeholders like title="..." are never concretized and no example fragment or markdown_representation sample is shown, so it falls short of fully copy-paste ready.

Workflow Clarity

The verify-and-save flow has an explicit validation step and a bounded feedback loop: 'fix all blockers together, regenerate once at the same output path, and reverify. If a blocker remains, stop and explain it instead of looping', followed by a sequenced save call. This matches the anchor for clear sequencing with explicit validation and error-recovery loops; no validation gaps are visible.

Progressive Disclosure

No bundle files exist and the four sections are well-organized with nothing that clearly belongs in a separate file, but at ~59 body lines it exceeds the under-50-line simple-skill exception, and the overlapping content between 'Authoring contract' and 'Web design requirements' is a minor organization gap. Good structure overall — fits the 'most content appropriately placed, minor gaps' anchor rather than the clean-split anchor.

Specificity

The description enumerates five concrete artifact types ('interactive calculators, configurators, dashboards, widgets, and prototypes') plus a concrete format constraint ('self-contained HTML artifacts'), which is several specific capabilities with only a minor gap — the single verb 'Create' omits the revise/edit workflow the body documents. It names far more than 1-2 actions (anchor 3) but is not comprehensive (anchor 5).

Completeness

The 'what' is clear (create self-contained interactive HTML artifacts of the listed kinds), but there is no 'Use when...' clause or equivalent explicit trigger guidance anywhere in the description, which caps completeness at 3 per the judging guidelines. The 'when' is only weakly implied by the artifact-type nouns.

Trigger Term Quality

Natural user terms are well covered — 'calculators', 'dashboards', 'widgets', 'prototypes', 'configurators', 'HTML' are all phrases users would plausibly say. A few natural variants are missing (e.g., 'web app', 'web page', 'single-file', '.html'), so it fits 'good keyword coverage; a few natural terms missing' rather than comprehensive synonym/extension coverage.

Distinctiveness Conflict Risk

'Self-contained HTML artifacts' combined with the specific artifact types carves a mostly distinct niche with minor overlap risk against generic frontend/web-development or visualization skills. It is more distinct than the 'could still overlap with similar skills' anchor but lacks the explicit distinct triggers of the top anchor.