Conciseness

The body is nearly all payload: six terse instructions, three worked examples, and one-line glossary entries that the skill explicitly instructs to "Quote the glossary verbatim" since "Its descriptions are authoritative" — so even well-known terms earn their tokens as the controlled vocabulary. No padded explanations of concepts Claude already knows, and the anti-drift check against anchor 4 finds no trimmable over-explanation.

Actionability

Fully executable guidance for an instruction-only skill: a copy-paste output template ("**Stagger** — Animate several items one after another with a small delay between each, creating a cascade."), three concrete input→output examples covering feel-based, disambiguation, and physics cases, and named confusable pairs ("Clip-path vs Mask, Pop in vs Bounce, Shared element transition vs Layout animation").

Workflow Clarity

A clear six-step sequence covering the happy path ("Read for intent, not keywords"), disambiguation, the no-match fallback ("name the closest term and say plainly it's an approximation"), and scope enforcement ("say so rather than inventing one"). This is a single-purpose lookup skill with an unambiguous action, and no destructive or batch operations exist, so no validation cap applies.

Progressive Disclosure

Well-organized sections (Quick Start, Instructions, Examples, ten categorized glossary groups) with clear headers, but the ~120-line glossary is inlined entirely in SKILL.md with no references. Inlining is defensible since every lookup needs the full vocabulary, yet the skill exceeds the under-50-lines simple-skill threshold, matching anchor 4's 'most content is appropriately placed; minor organization gaps' rather than 5's ideal split.

Specificity

The description names the domain ("web animation or motion effect") and one concrete action ("turns a vague description ... into its exact term") with worked examples, but lists only that single lookup capability rather than several specific actions, matching the 1-2-concrete-actions anchor. It is above anchor 2 because the named action is concrete and illustrated, but below anchor 4 because no additional specific capabilities are stated.

Completeness

It explicitly answers what ("Reverse-lookup glossary that turns a vague description of a web animation or motion effect into its exact term") and when ("Use when the user asks 'what's it called when…', or describes a motion effect without knowing its name"), with concrete trigger phrases and a boundary clause ("For naming an effect, not designing or building one").

Trigger Term Quality

It includes the exact natural phrases users would say — "what's it called when…", "the bouncy thing when a popover opens", "the iOS rubber-band scroll", "motion effect", "the right word to prompt an AI or designer" — covering synonyms and colloquial descriptions comprehensively; no file extensions apply in this domain. Anchor 4 would require natural terms to be missing, and none are.

Distinctiveness Conflict Risk

A clear niche (naming animation/motion effects) with distinct triggers, and the explicit negative boundary ("For naming an effect, not designing or building one") minimizes conflict with animation-design or build skills. Below-anchor check: anchor 4 requires minor overlap risk, but the boundary clause removes even that for the closest competing skill type.