Conciseness

The body is a lean task→library lookup: tables plus short decision rules, with zero explanation of concepts Claude already knows (it never explains what a toast or virtualization is). Every line either constrains behavior ("don't substitute alternatives outside this list", "don't churn the dependency without being asked") or adds a mapping; nothing is trimmable, matching anchor 5.

Actionability

The guidance is fully concrete for an instruction-only skill: named libraries with links for every task, an explicit package.json check, "recommend one library... install/wire it up", and boundary rules like "if data points arrive live and the chart scrolls with time, use Liveline. Everything else is recharts." The specific mappings cover the common cases, matching anchor 5 under the code-vs-instruction note.

Workflow Clarity

The four-step "How to use this" sequence (identify the task → check what's installed → recommend one → explicitly say when the list doesn't cover it) is unambiguous and handles both edge cases (existing competitor dependency, uncovered task). This is a single-purpose non-destructive skill, so the missing-validation cap does not apply and the simple-skill exception holds — anchor 5.

Progressive Disclosure

No bundle files exist, and none are needed: the skill is a self-contained ~72-line lookup table where splitting the table out would hurt lookup speed. Sections are cleanly organized (UI primitives, motion, charts, interaction, state/styling, mismatches), navigation is trivial via headers, and there are no nested references — matching anchor 5's 'content appropriately split, easy navigation'.

Specificity

"Pick the right library for a given frontend task from a curated, opinionated list" names a concrete action and domain, and the enumerated categories ("numbers, OTP inputs, charts, command menus, virtualization, drag and drop, toasts, state, styling") give specific coverage. It stops short of anchor 5 because the trailing "and more" hedges coverage and it names task categories rather than multiple distinct actions.

Completeness

The "what" is clear (pick the right library from a curated list for a frontend task), and "Only runs when explicitly invoked; it does not trigger on its own" is explicit trigger guidance, so the missing-'Use when' cap at 3 does not apply. It fits anchor 4 rather than 5 because the invocation-mechanics sentence describes when it runs, not the task conditions under which it should be used.

Trigger Term Quality

Terms like "OTP inputs", "command menus", "virtualization", "drag and drop", and "toasts" are exactly what users say when they need this skill. A few natural terms are missing (animation, dialogs/dropdowns, dark mode/theme switching), keeping it at anchor 4 rather than 5.

Distinctiveness Conflict Risk

The niche (choosing among a curated set of frontend libraries) is clear and distinctive terms like OTP inputs and command menus carry minimal conflict risk. Broad words like "charts", "state", and "styling" create minor overlap with related skills (e.g., charting or styling skills), so it sits at anchor 4 rather than 5.