Conciseness

The body is per-line lean and assumes competence — every sentence carries non-derivable fiber specifics (ACES tone mapping on by default, shadows="percentage" versus the deprecated boolean, the fiber 9.8 Clock deprecation warning, the Html remount bug) with no re-explanation of React, JSX, or three.js basics. It falls short of 5 because time-sensitive version pins ("Targets three.js r186", "fiber 9.8.2, drei 10.7.9", "React 19.2") are scattered inline rather than consolidated into a single versioning or deprecation section, which the guidelines explicitly penalize.

Actionability

Every section provides complete, import-bearing, copy-paste-ready code covering the common cases (Quick Start Canvas, useFrame/useThree/useLoader, pointer events with capture, WebGPU async factory, AdaptiveDpr and PerformanceMonitor patterns), and props/APIs are given with concrete values — matching the fully-executable top anchor; it is not 4 because no section relies on pseudocode or leaves key details implied.

Workflow Clarity

The topic order forms a coherent progression (Quick Start, Canvas props, JSX scene graph, hooks, events, loading, drei helpers, performance, disposal, WebGPU, mistakes) and procedural sequences like Suspense placement and on-demand invalidation are shown concretely. It sits at 4 rather than 5 because it is reference-style material: validation knowledge (console warnings, black screens, WebGPU incompatibilities) appears as advisory prose rather than explicit checkpoints in a sequenced workflow.

Progressive Disclosure

Sections are clearly headed and navigable, and depth is deferred one level to sibling skills ("threejs-loaders - loader configuration... in depth", "threejs-performance - profiling... beyond fiber's adaptive tools") rather than nested further. It does not reach 5 because there are no bundle reference files at all — the drei-helpers survey and the WebGPU/TSL compatibility detail are inlined in a ~30KB SKILL.md where an ideal structure would split that bulk into references/.

Specificity

The description lists six concrete capability areas ("renderer setup, the scene graph as JSX, frame-loop, state and loading hooks, pointer events, and adaptive performance") plus both rendering backends ("on WebGL or with WebGPU and TSL"), matching the comprehensive-coverage anchor rather than the minor-gaps anchor at 4.

Completeness

Both what and when are explicit: the what enumerates the skill's scope in the first sentence, and the when is a concrete trigger clause ("Use when writing React components that render three.js"), matching the top anchor exactly; not 4, since the when-clause is explicit rather than improvable.

Trigger Term Quality

Natural keywords users would say are present ("three.js", "React Three Fiber", "drei", "React", "WebGPU", "render three.js"), but common synonyms like "R3F" and the package names "@react-three/fiber" / "@react-three/drei" are missing, fitting the "a few natural terms missing" anchor rather than the synonym-complete 5.

Distinctiveness Conflict Risk

The niche is sharply scoped to React Three Fiber and drei within three.js work, so it is unlikely to trigger for plain three.js, non-React WebGL, or React DOM work — a clear niche with minimal conflict risk, matching the 5 anchor rather than the minor-overlap 4.