Conciseness

The body is lean and assumes competence — no explanations of concepts Claude already knows, and the resource-map tree earns its tokens as navigation. It sits at 4 rather than 5 because two rules are stated twice: the no-orphan-draft rule appears in Step 1 ("Do not write a project-root HTML draft with file-write...") and again in the Output contract ("Do not also write another root HTML file"), and the "one sentence before / nothing after" instruction is repeated in Step 5 and the Output contract.

Actionability

Every step is executable: named files to read ("Read `assets/template.html` end-to-end"), a concrete decision table of default section rhythms per page kind, a specific copy-swap convention ("Replace bracketed `[REPLACE]` strings"), and a copy-paste-ready output contract block. As an instruction-only skill the guidance is fully concrete and covers the common cases (landing, marketing, pricing, docs).

Workflow Clarity

Steps 0-5 are clearly sequenced with an explicit validation checkpoint ("Run through `references/checklist.md` top to bottom. Every P0 item must pass before you move on") and error-recovery guidance ("if a slot is empty, the section is the wrong choice; pick a different layout"; missing classes go into `<style>`). The pre-flight gate of stating the section list before writing also catches redirection cheaply. Not a destructive/batch operation, so no validation cap applies.

Progressive Disclosure

The body is a true overview: a resource-map tree pointing to three real one-level-deep files (assets/template.html, references/layouts.md, references/checklist.md — all verified to exist and to match the body's claims of "8 paste-ready section skeletons" and "P0/P1/P2" tiers), with the class inventory and layout skeletons properly kept in layouts.md rather than inlined. Navigation is easy and nothing is nested beyond one level.

Specificity

"Single self-contained HTML file built by copying the seed `assets/template.html` and pasting section layouts from `references/layouts.md`" names the domain and several concrete actions (copy seed, paste layouts, produce one HTML file). It falls short of 5 because it omits other capabilities the body covers (design-token mapping, self-check) and above 3 because more than 1-2 specific actions are stated.

Completeness

It answers both: what ("General-purpose desktop web prototype. Single self-contained HTML file built by...") and when ("Default for any landing / marketing / docs / SaaS page when no more specific skill matches"). Not 5 because the when-clause is routing-oriented (fallback default) rather than explicit user-trigger phrasing like "Use when the user asks for a mockup or landing page".

Trigger Term Quality

The description includes natural phrases users would say — "web prototype", "landing / marketing / docs / SaaS page", "single self-contained HTML file" — but misses common variations like "mockup", "homepage", or "website". Good coverage with a few natural terms missing matches anchor 4; the frontmatter's separate triggers list is not part of the description field.

Distinctiveness Conflict Risk

"General-purpose" and "any landing / marketing / docs / SaaS page" is broad and could overlap with more specific page-building skills, but the explicit yield clause "when no more specific skill matches" defines a clear fallback niche that reduces wrong-trigger risk. Mostly distinct with minor overlap risk matches anchor 4; anchor 3 would apply if it lacked that routing qualifier.