Conciseness

The ~25-line body is entirely instructional with zero padding — phrases like "Map the module (files, patterns, dependencies, Pages Router usage)" and "getServerSideProps -> async Server Component" convey dense specifics telegraphically without explaining any concept Claude already knows. It assumes competence throughout; every token earns its place.

Actionability

Guidance is mostly executable: exact directory layouts ("Create `src/modules/[name]/` (components/, hooks/, services/, adapters/, stores/, actions/, types/, __tests__/)"), exact file conventions ("Create `.types.ts` + `.contracts.ts` + adapter"), and specific tech mappings (React Query, Zustand, Server Actions). Minor gaps: no copy-paste validation commands ("Validate build/tsc/tests" names the checks but not the commands), and "Use `@migrator`" presumes the agent is already known. Not a 5 because nothing is copy-paste ready; not a 3 because the guidance is concrete and specific, not pseudocode or high-level hints.

Workflow Clarity

Seven phases are clearly numbered and sequenced, with an explicit repeated checkpoint ("Validate build/tsc/tests after each phase. Ask for approval before each phase.") — so the destructive/batch cap at 3 does not apply since validation is present. It falls short of the 5 anchor because there is no explicit error-recovery feedback loop (what to do when build/tsc/tests fail) and no checklist for the complex 7-phase process.

Progressive Disclosure

Per the rubric's simple-skill guidance, an under-50-line skill with no need for external references can score 5 with well-organized sections. The body is ~25 lines, cleanly sectioned, and its one external pointer (`docs/ARCHITECTURE.md`) is a clearly signaled, one-level-deep project reference rather than a nested skill reference.

Specificity

It names the domain ("a complete module needs migration to the target architecture") and one process-level detail ("runs 6 phases with approval gates"), but never states what the migration actually does — no mention of restructuring into modules/, converting Pages Router to App Router, or migrating state/data layers. This matches anchor 3 (domain plus 1-2 concrete actions, not comprehensive); it exceeds anchor 2 because the phase/gate detail is more than a generic one-liner, and falls short of anchor 4's 'several specific actions'.

Completeness

It has an explicit trigger clause ("Use when a complete module needs migration to the target architecture") and a 'what' ("runs 6 phases with approval gates"), so both halves are present — matching anchor 4. It is not a 5 because the 'what' is a process characterization rather than concrete capability statements, and the 'when' leans on the vague phrase 'target architecture' instead of concrete trigger phrases.

Trigger Term Quality

Relevant natural keywords are present ("module", "migration", "target architecture" — a user asking to 'migrate this module' would trigger it), but common variations are missing: no 'refactor', 'port', 'rewrite', 'convert', or the technology names (Next.js, App Router, Pages Router) users would naturally mention. This fits anchor 3 (some relevant keywords, missing common variations/synonyms) rather than anchor 4's 'good coverage with only a few missing'.

Distinctiveness Conflict Risk

The scope qualifier "a complete module" plus the phase/gate structure distinguishes it from smaller-scope migration or refactoring skills, giving it a fairly clear niche with only minor overlap risk against closely related migration skills. It is not a 5 because 'migration to the target architecture' is generic enough to overlap with any refactor/rewrite skill since the target architecture is never named.