Conciseness

The body is lean and directive throughout — "Prototype 是用来回答一个问题的 throwaway code。问题决定形状" sets framing in one line, and each of the six rules (e.g. "不写 tests，不做超过“能跑起来”所需的 error handling") adds only project-specific policy. No concept Claude already knows is explained; every token earns its place.

Actionability

Concrete, instruction-level guidance dominates: launch via "`pnpm <name>`、`python <path>`、`bun <path>`", a double-clickable single HTML file, "通过 URL search param 和浮动底栏切换", scratch DBs named "PROTOTYPE — wipe me", and commit-to-throwaway-branch capture. As an instruction-only skill this is actionable without code, but it is not 5: the commands are placeholders rather than a worked example (e.g. a sample package.json script or a minimal variant-switching snippet), and branch details are delegated out.

Workflow Clarity

The sequence is clear: identify the question ("来自用户 prompt、周围代码，或在用户在线时直接询问") → pick a branch with an explicit tie-breaking default ("backend module → logic；page 或 component → UI") → build under the six rules → "完成后 capture". Checkpoints exist implicitly (rule 5's expose-state after every action, capturing only "验证过的 decision") but there is no explicit validate-with-user/fix loop, keeping it below 5.

Progressive Disclosure

The structure itself is good — a short overview that cleanly delegates the two branches to well-signaled, one-level-deep links ([LOGIC.md](LOGIC.md), [UI.md](UI.md)). However, neither LOGIC.md nor UI.md exists in the bundle (no references/, scripts/, or assets/ directories are present), so the branch-specific instructions the overview points to are unreachable; navigation is broken rather than easy, which drops it below 4.

Specificity

"构建一次性原型来回答一个设计问题" names the domain (throwaway prototyping) and one concrete action (build a prototype to answer a design question), but stops there — it never says what the artifacts are (single shareable HTML file, switchable UI variants), matching the '1-2 concrete actions, not comprehensive' anchor. It is not 4 because there are not several distinct specific actions listed.

Completeness

It has an explicit what ("构建一次性原型来回答一个设计问题") and an explicit use-when clause ("适用于用户想验证…或探索…时") with two concrete trigger scenarios, so it clears the level-3 cap for a missing use-when clause. It is not 5 because the 'what' remains high-level — it does not concretely state what gets built (an HTML state-machine demo, UI variation routes).

Trigger Term Quality

"验证某个 state model 或 logic 是否感觉对" and "探索 UI 应该长什么样" are natural phrases a user would say, so this is above level 2, but coverage is narrow — missing common synonyms users would reach for such as mock, demo, spike, POC, or wireframe. That fits 'some relevant keywords but missing common variations or synonyms'.

Distinctiveness Conflict Risk

The niche is distinctive — throwaway prototypes built to answer a single design question, split into logic/state-model validation vs UI exploration — with triggers unlikely to fire for unrelated skills. It is not 5 because it could still mildly overlap with generic frontend-design or diagramming/mockup skills given no artifact details distinguish it.