The body is mostly efficient and avoids explaining concepts Claude already knows, but it could be tightened: the output structure is described three times (the 'Outputs' list, Core Workflow step 6's report, and the 'Output Format' block) and the rhetorical opener 'The goal is not to guess what "feels useful."' earns little. This fits 'mostly efficient but includes some unnecessary explanation or could be tightened' rather than the level-3 'every token earns its place'.

Provides fully executable guidance: concrete commands (`rg --files`, `rg -n "typescript|react|..."`, `cat package.json`), a copy-ready evidence-table format with worked rows, specific paths (`.claude/skills/skill-library/SKILL.md`), and a concrete output template — matching the level-3 'fully executable code/commands; specific examples; copy-paste ready' anchor.

A clear six-step Core Workflow with an explicit validation checkpoint: step 6 'Verify the result' lists checks (every DAILY file exists, no stale rules left active, no incompatible hooks installed, install matches repo stack). Because this batch operation has an explicit verification checklist, it clears the cap that would otherwise limit workflow clarity to 2, matching the level-3 'clear sequence with explicit validation steps; checklists' anchor.

No bundle files exist in references/scripts/assets, and the skill is a single self-contained file with well-organized sections (When to Use, Classification Model, Evidence Sources, Core Workflow, Handoffs, Output Format). Per the rubric note, a skill with no need for external references scores 3 on progressive disclosure when its sections are well organized; it is above level 2 because nothing that should be split out is inlined.

Names multiple concrete actions: 'Build an evidence-backed ECC install plan', 'sorting skills, commands, rules, hooks, and extras into DAILY vs LIBRARY buckets', 'using parallel repo-aware review passes' — closely matches the 3-anchor example of listing several specific concrete actions.

Explicitly answers both 'what' (build an evidence-backed install plan by sorting components into DAILY vs LIBRARY via parallel review passes) and 'when' ('Use when ECC should be trimmed... instead of loading the full bundle'), matching the level-3 anchor that requires explicit triggers for both.

The trigger 'Use when ECC should be trimmed to what a project actually needs instead of loading the full bundle' offers relevant phrases, but leans on niche jargon (ECC, DAILY/LIBRARY) and omits common natural variations like 'install only the skills this project needs' or 'project-specific install'; it is not the level-3 'good coverage of natural terms users would say' and is above level 1 because some usable trigger words are present.

The niche is sharply defined — repo-specific ECC trimming via a DAILY/LIBRARY sort — with triggers unlikely to fire for unrelated skills, matching the level-3 'clear niche with distinct triggers; unlikely to conflict' anchor rather than the overlap-prone level-2 example.