Conciseness

The body mostly avoids explaining concepts Claude already knows and leads with runnable code, but contains real redundancy: the full Bun.build options block, a near-identical 'Build Output' block, and a 'Build Script' block all repeat the same try/catch pattern three times, and the three Target Environments sections each show the same config differing only in one string. This is 'mostly efficient but includes some unnecessary explanation or could be tightened' (anchor 3), not anchor 4's 'minor instances'.

Actionability

Examples are fully executable and copy-paste ready: CLI commands, a complete Bun.build options object with valid values annotated, a working plugin with onResolve/onLoad hooks, output iteration, and a Common Errors table with cause/fix. The examples cover the common cases (browser/node/bun targets, production, library, build script) — matching anchor 5's 'copy-paste ready code covering the common cases'.

Workflow Clarity

The path from quick start through configuration to common patterns is clearly sequenced, and the Common Errors table provides error-recovery guidance, but there are no explicit validation checkpoints (e.g., verifying outputs landed in ./dist or inspecting chunk counts). Builds are not destructive/batch edits of user data, so the workflow-clarity cap at 3 does not apply; this is anchor 4 ('clear sequence with most checkpoints; minor validation gaps') rather than anchor 5's explicit validate-fix-retry loop.

Progressive Disclosure

The body has good section structure and an explicit 'When to Load References' section, but two of the three referenced files (references/plugins.md, references/macros.md) do not exist in the bundle, and the complete Bun.build options reference is inlined in SKILL.md even though references/options.md exists for exactly that purpose. Scoring against the actual bundle, this is anchor 3 ('references present but not clearly backed by real files; content that should be separate is inline') — the broken reference paths and inlined bulk rule out anchor 4.

Specificity

The description names the domain clearly ('bundling with Bun') and the trigger list enumerates concrete feature nouns like "code splitting", "tree shaking", "minification", and "sourcemaps", but it never states concrete actions the skill performs — there is no 'bundles', 'configures', or 'optimizes' verb phrase. This sits between anchor 2 ('actions are minimal or generic') and anchor 4 ('lists several specific actions'), matching anchor 3's domain-plus-limited-concrete-capabilities level.

Completeness

The 'when' is explicitly and thoroughly answered ('This skill should be used when the user asks about...'), but the 'what' is entirely absent — the description never says what the skill does (e.g., 'Documents Bun's bundler API and CLI...'). This matches anchor 2 ('only when is present without what') exactly; it cannot be a 3 because anchor 3 requires a clear 'what'.

Trigger Term Quality

Trigger terms are comprehensive and natural: "bun build", "Bun.build", "bundling with Bun", "code splitting", "tree shaking", "minification", "sourcemaps", "esbuild alternative", "building for production", "bundling TypeScript", "bundling for browser", "bundling for Node" — covering the CLI name, the API name, synonyms, and task-level phrasings a user would actually say. It is not below anchor 5 because essentially no natural variation for this domain is missing.

Distinctiveness Conflict Risk

Bun-specific triggers ("bun build", "Bun.build", "bundling with Bun") are highly distinct, but generic bundler terms like "minification", "code splitting", "tree shaking", and "building for production" would also match an esbuild or webpack skill. This is 'mostly distinct; minor overlap risk with closely related skills' (anchor 4), not anchor 5, since several triggers are not Bun-exclusive.