Conciseness

The body is a lean, well-organized rule list that assumes Claude's competence and avoids explaining concepts it already knows; every rule earns its place with no padding.

Actionability

It gives concrete, executable guidance (exact scale factors, specific material families, named hook signatures, validation commands), but the watch()/startRace() launcher guidance is described as a flow rather than copy-paste code, leaving a minor gap versus the score-5 anchor.

Workflow Clarity

Authoring rules are sequenced with clear checkpoints and an explicit Validation section including `node --check`, `tools/check.js`, and a visual check, providing the validation feedback loop the score-5 anchor calls for.

Progressive Disclosure

The skill is under 50 lines with no external references needed; it is organized into tight Rules and Validation sections, satisfying the simple-skill exception for a top progressive_disclosure score.

Specificity

The description names a concrete domain (Tinyverse ground-surface race track) and several concrete objects (perimeter bridge loop, rally karts, poser-surface show/hide hook), but frames them as 'changing' rather than listing distinct concrete actions, leaving coverage less comprehensive than the score-5 anchor.

Completeness

It explicitly answers 'what' (changing the Tinyverse ground-surface race track, perimeter bridge loop, rally karts, poser-surface hook) and 'when' via a clear 'Use when...' trigger clause, matching the score-5 anchor for both what and when.

Trigger Term Quality

It includes some natural terms a user might say ('race track', 'rally karts'), but most language ('perimeter bridge loop', 'poser-surface show/hide hook') is internal jargon users would rarely voice, missing common synonyms or variations.

Distinctiveness Conflict Risk

The trigger is a highly specific niche (Tinyverse race track / rally karts / poser-surface hook) unlikely to overlap with other skills, giving minimal conflict risk as in the score-5 anchor.