Conciseness

The body is lean and assumes Claude's competence: no explanation of HTML/CSS or design concepts, every line is spec ('12px black bezel, 44px corner radius', 'near-black #0e0d0c', '3×2 grid of quest tiles'). The quest-name examples and color note are load-bearing guidance, not padding — matching 'every token earns its place'.

Actionability

Guidance is concrete and executable for a design/prototyping skill: exact dimensions (360×780 frames), hex token (#0e0d0c), per-frame content lists, a tab-bar spec, an explicit 'no images, use linear-gradient and inline SVG' constraint, and a copy-paste artifact output template with identifier/type/title. Per the scoring notes, absence of code in an instruction-only skill is not penalized when guidance is this specific.

Workflow Clarity

A clear 9-step sequence (read DS → pick brand → stage → phones → per-frame content → write → self-check) with a step-9 checklist ('Three frames, each with a distinct purpose', 'Tile colors don't overpower', 'Reads as gamified and adult'). It falls short of anchor 5 because the self-check lists criteria but gives no remediation loop (what to change if a check fails), fitting anchor 4's 'clear sequence with most checkpoints present; minor validation gaps'. This is not a destructive/batch operation, so no cap applies.

Progressive Disclosure

The skill is self-contained: no references/, scripts/, or assets/ bundle exists, and the only external mention ('Read the active DESIGN.md (injected above)') is a platform-injected file, clearly signaled. Sections are well organized (Workflow, Output contract) and nothing belongs in a separate file, fitting anchor 4's 'good structure; most content appropriately placed'. It does not take the anchor-5 exception because the body is ~74 lines — over the simple-skill (<50 line) threshold — even though the organization is clean.

Specificity

The description names concrete deliverables — 'three phone frames on a dark showcase stage', 'Frame 1: cover / poster, Frame 2: today's quests with XP ribbons and a level bar, Frame 3: quest detail', 'Vivid quest tiles, level ribbon, bottom tab bar' — which is specific and near-comprehensive for a design skill. It stops short of anchor 5 because it describes one prototype artifact's components rather than a list of multiple distinct concrete actions, and it is well above anchor 3's '1-2 concrete actions' bar.

Completeness

It explicitly answers 'what' ('A multi-frame gamified mobile-app prototype — three phone frames... Frame 3: quest detail') and 'when' ('Use when the brief asks for a "gamified app", "habit tracker", ...') with concrete trigger phrases. This directly matches the anchor-5 example structure and is not the anchor-4 case, since the 'when' clause is explicit and specific rather than improvable.

Trigger Term Quality

The 'Use when' clause enumerates natural user phrasings with synonyms — "gamified app", "habit tracker", "RPG-style life app", "level-up app", "daily quests", "XP / streak app", "ELI5-style explainer app" — and the frontmatter triggers list adds more variations including CJK terms ("游戏化", "习惯打卡"). This is comprehensive synonym coverage matching the anchor-5 example's breadth.

Distinctiveness Conflict Risk

The niche is tightly defined — a gamified RPG-style prototype showcase with XP/quest/level triggers — making it unlikely to fire for unrelated skills. Terms like "habit tracker" carry only minimal overlap risk with a generic tracker brief, and the gamified framing throughout disambiguates; this fits 'clear niche with distinct triggers; minimal conflict risk'.