Conciseness

The body is lean and dense: every section is minimal prose plus commented executable code, it assumes reader competence (no explanation of what three.js or animation is), and version-sensitive details (r186 target, Clock deprecated in r183) are concentrated in a Common Mistakes section rather than scattered.

Actionability

All examples are copy-paste-ready and complete — renderer/scene/camera setup, mixer/action lifecycle, crossfades, glTF loading with lights, bone overrides, morph targets, additive blending, and TSL node materials — covering the common cases with correct, specific API calls (e.g. track-name syntax, Bezier tangent layout).

Workflow Clarity

Multi-step flows are clearly sequenced (load glTF → add lights → create mixer → play → per-frame timer.update()/mixer.update()/render), and ordering constraints are made explicit ("Procedural bone control runs after mixer.update()"). However, there are no explicit validation checkpoints or error-recovery loops, though the domain (rendering, non-destructive) does not demand the destructive/batch cap.

Progressive Disclosure

No bundle files exist, so scoring is against the in-body organization: sections are well-ordered with a Quick Start up front, and the See Also section cleanly points one level to sibling skills. The ~500-line body is navigable, though specialized material (WebGPU/TSL, glTF loading) could arguably be split into reference files.

Specificity

The description lists multiple concrete capabilities — "Keyframe, skeletal and morph-target animation, procedural motion and clip blending, on WebGL or with WebGPU and TSL" — covering the domain comprehensively with no vague filler.

Completeness

It clearly answers 'what' (keyframe, skeletal, morph-target animation, procedural motion, clip blending, WebGL/WebGPU/TSL) and explicitly answers 'when' with concrete trigger phrases in a proper "Use when..." clause.

Trigger Term Quality

The "Use when" clause lists natural phrases users would say ("animating objects, playing glTF animations, posing bones, driving morph targets, or mixing and crossfading clips"), but misses common variations like "character animation", ".glb/.gltf files", or naming three.js itself in the description text.

Distinctiveness Conflict Risk

The TSL/WebGPU and bone/morph-target triggers carve a clear animation niche with minimal generic risk, but "playing glTF animations" slightly overlaps a sibling loaders skill and the description never names three.js (only the frontmatter name does), leaving minor overlap risk with closely related skills.