Conciseness

Lean and efficient throughout: code-first examples with no padding, assumes Claude's TypeScript competence, and every explanatory section (the U+200B rationale, the arkregex/never/unique-symbol comparisons) earns its place with concrete justification.

Actionability

Fully executable, copy-paste-ready code for the predicate, branded error type, helper, and runtime-checked variant, plus four concrete mistakes with fixes — covering the common cases completely.

Workflow Clarity

As a single-purpose pattern reference the application is unambiguous, and the 'Where to put the runtime check' section pairs the type-level check with a concrete runtime validation path and enumerates the bypass cases.

Progressive Disclosure

Well-signaled, one-level-deep structure (pattern, why-the-suffix, anatomy, alternatives, pitfalls, reference) with a final Reference block pointing to concrete file paths; no bundle files exist, so the self-contained body is appropriately organized.

Specificity

Names multiple concrete actions (branding constraint-violation types as template literal messages, appending a U+200B zero-width-space suffix) with comprehensive coverage of the technique, matching the 'lists multiple specific concrete actions' anchor.

Completeness

Explicitly answers both what ('Make compile-time errors readable by branding...') and when ('Use when writing helper functions that constrain object keys...') with concrete trigger phrases, matching the 'clearly and explicitly answers both what AND when' anchor.

Trigger Term Quality

Good keyword coverage ('helper functions that constrain object keys, string shapes, or other literal-type inputs', 'TypeScript error tooltip'), but lacks the breadth of synonyms and varied natural phrasings that would mark it comprehensive.

Distinctiveness Conflict Risk

Targets a clear niche (type-level branded template-literal error messages in TypeScript) with distinct triggers and minimal overlap risk with other skills.