Conciseness

Nearly all content is jscpd-specific knowledge Claude cannot have (calibrated thresholds like "0.4125 across languages and 0.6375 within one language", module-linking rules, report block shapes) and it avoids explaining known concepts. A few dense multi-clause sentences (the module-definition paragraph in the name-pairing step) and the test-convention list could be tightened, which keeps it just below a 5.

Actionability

Fully executable, copy-paste-ready commands throughout ("npx jscpd --compare billing-py/ billing-ts/", "-r console-full", "--ignore \"**/vendor/**,**/target/**,**/node_modules/**\"", "--semantic-download"), a complete annotated sample of the console output, and a documented JSON report schema. The common cases (port progress, tests-only, code-only) are each covered with the exact flag to use.

Workflow Clarity

Six clearly sequenced steps with explicit validation checkpoints: step 4 instructs reading a sample of high/low/by-name pairs "before reporting the comparison as reliable", step 5 requires searching the other folder before calling a function missing, and error handling is specified ("When a sample pair is wrong, say which one and why"). This is not a destructive or batch operation, so no validation cap applies.

Progressive Disclosure

Well-sectioned single-file skill with clear headings and one-level-deep, clearly signaled cross-references to sibling skills; the structure is easy to navigate. It falls short of 5 because the two outbound links (../code-migration/SKILL.md, ../jscpd/SKILL.md) do not resolve within this bundle, and roughly 35 lines of pairing-algorithm internals are inlined in SKILL.md where a reference file could hold them.

Specificity

Names concrete actions with the tool and mechanism ("Compare two folders function by function with jscpd --compare", "explain the result") plus the same-language/cross-language scope. It stays below 5 because capability coverage is not comprehensive — report formats, migration maps, and options are not mentioned — and above 3 because the actions are specific rather than generic.

Completeness

Explicitly answers both questions: the first sentence states what the skill does (function-by-function comparison with jscpd --compare plus explaining the result), and "Use when asked how two codebases relate, …" gives concrete when-triggers.

Trigger Term Quality

Five natural phrasings users would actually say: "how two codebases relate", "which functions one implementation has and the other lacks", "how far a port has come", "whether the iOS and Android versions of an app match", and "which function in one folder corresponds to a function in the other". Coverage includes synonyms and concrete platform examples.

Distinctiveness Conflict Risk

A clear niche (two-folder function-level comparison) with distinct triggers, but "how far a port has come" tugs toward the closely related code-migration skill the body itself defers to, creating minor overlap risk rather than minimal.