Conciseness

The Pragmatic Balance and Feedback Loop sections earn their tokens (e.g., the containsKey/omitted-key vs explicit-null semantics is genuinely non-obvious), but 'Core Pattern Implementations' restates the Dart language spec Claude already knows ('Throws if the value does not match the type', 'Matches any value and discards it'). Mostly efficient with a clearly trimmable section — matches anchor 3, not 4, because the language-spec restatement is a substantive chunk of padding rather than a minor instance.

Actionability

Prefer/Avoid code pairs are executable and specific, and 'Run analyzer: Execute dart analyze' with the exact compiler message to look for is concrete. Not 5: two Examples sections promise an executable implementation at examples/json_patterns.dart, which does not exist in the bundle — copy-paste-ready coverage of the JSON cases is therefore incomplete.

Workflow Clarity

A copyable task checklist plus two explicit feedback loops (analyzer error → add missing arm → re-validate; runtime omitted-key vs explicit-null verification) matches the top anchor: explicit validation steps, error-recovery loops, and a checklist for a complex process. Not 4: the checkpoints are explicit commands and verifications, not implicit.

Progressive Disclosure

Good structure (contents list, clear section headers), but no bundle files exist while the body references a nonexistent examples/json_patterns.dart twice, and ~40 lines of language-spec syntax reference are inlined that belong in a separate reference file. Matches anchor 3 — structure present, but content that should be separate is inline and a reference does not resolve; not 4 because a broken referenced path is more than a minor organization gap.

Specificity

Lists multiple specific concrete actions — 'validate data schemas', 'handle algebraic data types', 'decompose control flow', 'parsing polymorphic JSON or API responses', 'enforcing exhaustiveness on sealed classes' — with comprehensive coverage across validation, ADT handling, and destructuring targets.

Completeness

Explicitly answers both 'what' (applies Dart 3 pattern matching, switch expressions, and destructuring to validate data schemas...) and 'when' (an enumerated 'Use when...' clause with concrete trigger phrases), and adds a 'Don't use for...' boundary clause that exceeds the anchor-5 example.

Trigger Term Quality

Comprehensive natural trigger terms with synonyms: 'pattern matching', 'switch expressions', 'destructuring', 'refactoring complex if-else chains', 'URI/path segments', 'String.split() tokens', 'Records', 'Maps', 'sealed classes', plus negative triggers ('simple boolean conditions', 'single-variable type promotion'). No common variations are missing for this domain.

Distinctiveness Conflict Risk

Occupies a clear Dart 3-specific niche (sealed classes, Records, switch expressions, exhaustiveness) with negative triggers distinguishing it from plain `is` type promotion and basic filtering — minimal conflict risk with other skills.