Conciseness

The ~40-line body is lean with zero padding: an install command, a version requirement, one complete example, and a one-row API table. No concept Claude already knows is explained, matching the 'every token earns its place' anchor rather than the level-4 'minor instances of over-explanation'.

Actionability

The usage example is fully executable and copy-paste ready (imports, createAtom, xstateStoreStateStore, StateProvider) and covers the common case end-to-end, with a concrete option table. This matches the top anchor; there are no gaps that would place it at level 4.

Workflow Clarity

The integration steps are explicitly numbered ('1. Create an atom', '2. Create the json-render StateStore adapter', '3. Use it') with no ambiguity. This is a simple, single-purpose, non-destructive skill, so per the rubric's simple-skill exception a clear unambiguous single action can score 5 without additional validation checkpoints.

Progressive Disclosure

The skill is under 50 lines, has no bundle files (references/, scripts/, assets/ do not exist), and needs none — the one option and one example fit comfortably in the body. Sections (Installation / Usage / API) are well-organized, which per the rubric's under-50-lines guideline merits the top score.

Specificity

The description names the domain precisely ("XState Store adapter for json-render's StateStore interface") but states only one action — adapting/wiring — without listing what the adapter actually does (read, write, subscribe to state). This matches the anchor 'Names domain and 1-2 concrete actions, but not comprehensive' and falls short of the level-4 anchor, which expects several specific actions.

Completeness

It explicitly answers both: what ('XState Store adapter for json-render's StateStore interface') and when ('Use when integrating json-render with @xstate/store for state management via @json-render/xstate'), with concrete trigger phrases. This is a direct match for the top anchor; the level-4 anchor ('when could be more explicit') does not apply since the when-clause is already explicit and specific.

Trigger Term Quality

Good keyword coverage: 'XState Store', '@xstate/store', 'state management', 'json-render', '@json-render/xstate' — the natural vocabulary for this integration. It is not a 5 because a few natural phrasings users might say (e.g., 'wire xstate to json-render', 'use xstate as the state backend') are missing, but it clearly exceeds the level-3 anchor's 'missing common variations'.

Distinctiveness Conflict Risk

The trigger is a highly specific package pairing (json-render + @xstate/store) that no other plausible skill would share, giving a clear niche with minimal conflict risk — matching the top anchor rather than the level-4 'minor overlap risk with closely related skills'.