Conciseness

Every section is a lean, executable example with only library-specific gotchas explained (e.g., 'waitForNextUpdate() - Deprecated: it gives up silently after 1 second...', 'Remember nextTick() - After mutations/setResponse...'). No space is spent explaining concepts Claude already knows (what jest/nock/Vue are), and the deprecated-API note is appropriately framed as deprecated.

Actionability

The body provides copy-paste-ready, fully executable code for the common cases: useQuery with initialFixtures, mountDataClient component test with reactive props, prop-change and null-handling patterns, mutation via controller.fetch, setResponse reactivity, a minimal nock shape, and a fake-timer polling test. The one external dependency (flushUntil) is explicitly directed to be copied from a linked reference with a section anchor.

Workflow Clarity

Multi-step processes are explicitly sequenced with checkpoints: the polling flow is a numbered 4-step sequence (fake timers before mount → advance → mutate/advance + await allSettled() + nextTick() → restore real timers in afterEach), and flushUntil 'throws if the condition never holds', providing an explicit failure signal rather than a silent wait. Mutation and prop-change flows each show the exact await/tick checkpoints.

Progressive Disclosure

The SKILL.md body keeps core patterns inline and appropriately splits detail into six real one-level-deep reference files (Fixtures, mockInitialState, unit-testing-components, unit-testing-composables, nock-http-mocking, polling-subscriptions — all verified to exist). References are clearly signaled both inline at the point of need and in a dedicated References section with descriptive labels, making navigation easy.

Specificity

The description names the domain ('Test @data-client/vue composables and components') and lists multiple concrete capabilities: 'renderDataCompose, mountDataClient, fixtures, jest, nock HTTP mocking, polling/subscription tests with fake timers, useSuspense, useLive, useSubscription, Vue 3 reactive props' — comprehensive coverage of the skill's scope, matching the anchor for multiple specific concrete actions.

Completeness

It explicitly answers both what ('Test @data-client/vue composables and components - renderDataCompose, mountDataClient, fixtures, jest, nock HTTP mocking, polling/subscription tests...') and when ('Use when writing or debugging tests for composables or components built on @data-client/vue') with concrete trigger phrases, matching the top anchor.

Trigger Term Quality

Good natural keyword coverage — 'test', 'composables', 'components', 'fixtures', 'jest', 'nock', 'polling', 'subscription', 'fake timers', 'reactive props' are phrases a user would naturally say — but common variations such as 'unit testing' or 'mock fetch/mocking' are missing, which fits the anchor for good coverage with a few natural terms absent rather than comprehensive synonym coverage.

Distinctiveness Conflict Risk

The '@data-client/vue' qualifier plus library-specific API names (renderDataCompose, mountDataClient, useSuspense, useLive) establish a clear niche with distinct triggers; only minimal breadth comes from generic terms like 'jest' or 'Vue 3 reactive props', so conflict risk with other skills is minimal.