Conciseness

The body is checklist-style with no filler or teaching of concepts Claude already knows, but the 'Working Pattern' risk list (lines 25-49) and long stretches of 'Coverage Heuristics' / 'Output Expectations' accumulate ~20 niche scenario bullets (AR/camera/motion/geolocation, globe/terrain/cutaway, Codex image-generated concepts, fictional story simulations, scrollytelling trigger ranges) that belong in the reference files or sibling skills. This is 'could be tightened' at scale — more than the 'minor instances' of anchor 4, but the content is substance rather than the padded explanation of anchor 2, so it sits at 3.

Actionability

As an instruction-only skill the guidance is concrete and specific: 'fixed viewport and container size', 'stable fonts, theme tokens, locale, and timezone', 'prefer mocked network responses, data loaders, or repository adapters', plus concrete coverage mappings (unit tests for 'scales, domains, bin boundaries, sort rules'). It is not the pseudocode/vague anchor 3, but it stops short of anchor 5's copy-paste-ready examples — no runnable snippet or command appears in the body (the Playwright starter lives in a referenced template), so a few common cases lack an executable example.

Workflow Clarity

The 'Working Pattern' is a clear 6-step sequence (identify risks -> choose layer -> make deterministic -> mock at boundary -> non-goals -> live modes) with some implicit checkpoints ('explicit render-ready signals before capture', 'start with the narrowest high-value slice'). It matches anchor 4 ('clear sequence with most checkpoints present; minor validation gaps') rather than 5, because there is no explicit validate/fix/retry feedback loop (e.g., re-run a flaky baseline or confirm determinism before locking a baseline). The destructive/batch cap does not apply — this is a strategy skill.

Progressive Disclosure

Structure is good: overview, when-to-use, working pattern, heuristics, output expectations, a clearly grouped References section, and representative prompts. All six local reference files (test-level-selection.md, unit-and-component-tests.md, visual-regression-and-image-testing.md, data-mocking-and-fixtures.md, e2e-dashboard-and-export-strategies.md, avoiding-brittle-over-testing.md) exist and are substantive, one level deep. Not anchor 5 because some content that belongs in those references (the niche WebGL/mobile/UML/scrollytelling scenario checklists) is inlined in the body, and many referenced paths (../../references/foundations/*, ../../assets/templates/*, sibling skills) resolve outside this bundle and cannot be verified from it.

Specificity

Beyond the clear core action ('Test data visualizations and dashboards'), the description enumerates multiple concrete capabilities: 'screenshot or image diff testing, visual regression, mocked or synthetic chart data, component or unit tests, E2E dashboard QA, ... export verification'. This matches the anchor 'Lists multiple specific concrete actions; comprehensive coverage' — the enumeration spans every testing layer of the domain, so it is not the level below (4, 'minor gaps in coverage').

Completeness

It explicitly answers what ('Test data visualizations and dashboards') and when ('Use when the user needs chart or diagram test strategy, ... or guidance on avoiding brittle over-testing') with concrete trigger phrases, exactly matching the anchor 'Clearly and explicitly answers both what AND when'. Not level 4, because the 'when' clause is not merely present but itemizes concrete triggering needs.

Trigger Term Quality

The description covers natural phrases users would actually say — 'test strategy', 'screenshot ... testing', 'image diff testing', 'visual regression', 'mocked or synthetic chart data', 'component or unit tests', 'E2E dashboard QA', 'brittle over-testing' — with synonym variation for each (screenshot/image diff, unit/component, mocked/synthetic). This matches the comprehensive-synonyms anchor rather than level 4, where 'a few natural terms' would be missing; no commonly-said testing trigger is absent.

Distinctiveness Conflict Risk

The niche is clear (testing/verifying visualizations rather than rendering them) and most triggers ('visual regression', 'image diff', 'test strategy') are owned by this skill. However, phrases like 'interactive UML-like diagram verification' and 'scroll-driven story verification' bleed into territory of closely related sibling skills (uml-and-software-architecture-visualization, scrollytelling-and-parallax), giving 'minor overlap risk with closely related skills' — the anchor-4 example — rather than the minimal-conflict anchor 5.