Conciseness

Efficient overall — nearly every section carries novel workflow instructions (verification gates, spec-change protocol, plan template) rather than concepts Claude already knows. Not 5 because of genuine redundancy: the lightweight path is stated twice ('Lightweight path (skip research...)' in Phase 0 and 'Lightweight path for simple changes' at the end), the workflow diagram duplicates the phase prose, and the 'What NOT to do' table reiterates rules already stated inline.

Actionability

Mostly executable: concrete commands ('quint typecheck', 'quint run' with '--max-samples 5000', 'quint verify', 'quint test'), a fill-in plan format, a status-compaction template, and a gap-analysis prompt. Not 5 because no complete copy-paste command invocations are shown (e.g. 'quint run spec.qnt --invariant <name>') and the REPL row ('quint REPL session' + 'quint REPL eval') is vague.

Workflow Clarity

Clear phased sequence (Phase 0-4) with explicit validation gates after each implementation step, feedback loops on failure ('If the gate fails: stop, diagnose, return to Phase 2'), rollback criteria, a violated-invariant recovery procedure, and an anti-pattern checklist. Matches the top anchor: explicit validation steps, error-recovery loops, and checklists.

Progressive Disclosure

Good structure: clear section headers, a workflow overview diagram, and a tool-usage table, all appropriately inlined for a single-file workflow skill (no bundle files exist). Not 5 because there are no reference files at all and the file is ~260 lines — the detailed phase bodies (plan format, spec-change protocol) could be split into one-level-deep references to keep SKILL.md a leaner overview.

Specificity

Lists several concrete actions — 'Implement code against an existing Quint specification', 'refactor code', 'add a new feature', 'close a gap between implementation and spec' — with only minor gaps in coverage (sub-actions like running verification gates are not enumerated). Not 5 because coverage is not comprehensive and 'ACE-FCA style' is unexplained jargon; not 3 because more than 1-2 specific actions are named.

Completeness

Explicitly answers both: what ('Implement code against an existing Quint specification. Uses Research → Plan → Implement workflow...') and when ('Use when the user wants to refactor code, add a new feature, or close a gap between implementation and spec') with concrete trigger phrases.

Trigger Term Quality

Good natural keyword coverage: 'refactor code', 'add a new feature', 'gap between implementation and spec', 'Quint specification'. Not 5 because common variations are missing — the '.qnt' file extension and phrases like 'spec-first' or 'implement from the spec' appear only in the body, not the description.

Distinctiveness Conflict Risk

Clear Quint-spec niche with distinct triggers and an explicit handoff boundary ('If no spec exists yet, use quint-modeling'). Not 5 because 'refactor code' and 'add a new feature' are generic phrases that a user could say in a non-Quint context, creating minor overlap risk with general coding skills.