Conciseness

The ~45-line body is mostly lean and instructional, but carries minor over-explanation Claude already knows ('Missing or incorrect charset causes mojibake (garbled text), broken special characters…', 'UTF-8 supports all languages and special characters') and repeats the meta-tag guidance across Quick Reference and Fix. Anchor 4 fits: efficient with minor instances that could be trimmed; not 5 since a few tokens don't earn their place.

Actionability

Concrete, executable guidance: 'Add <meta charset="UTF-8"> as the first element in <head>', 'Must appear within the first 1024 bytes', and 'Flag exact elements, attributes, and routes'. The exact tag and byte threshold are copy-paste-ready; anchor 4 rather than 5 because example markup and framework cases are deferred entirely to references/rule.md, leaving minor gaps in the body itself.

Workflow Clarity

A simple, non-destructive, single-purpose check with a clear Check → Fix → Explain → Code Review structure where the Check section acts as the validation checkpoint. Anchor 4 rather than 5: the sequence is clear and checkpoints mostly present, but there is no explicit re-verify-after-fix feedback loop.

Progressive Disclosure

Verified against the actual bundle: the body is a concise, well-sectioned overview; references/rule.md exists, is exactly one level deep, and is clearly signaled ('For full implementation details, code examples, and framework-specific guidance, see references/rule.md'). Content is appropriately split between overview and reference with easy navigation — matches anchor 5.

Specificity

Two concrete actions are named — 'reviewing templates, rendered HTML, or shared components' and 'Validate the final browser-facing markup' — with the concrete scoping instruction 'not just the source framework abstraction'. It sits between anchor 3 (1-2 actions, not comprehensive) and anchor 4 (several specific actions): noticeably more specific than anchor 3's example, but only two verbs rather than 'several'.

Completeness

Both parts are present: an explicit 'Use when reviewing templates, rendered HTML, or shared components…' trigger clause and a what ('Validate the final browser-facing markup'). Not anchor 5 because the 'what' is thin — it never states the concrete capability (adding/verifying the meta charset tag and its 1024-byte position).

Trigger Term Quality

Good natural-keyword coverage: 'templates', 'rendered HTML', 'shared components', 'UTF-8', 'character encoding'. Not anchor 5 because common user phrasings are missing — 'charset' itself never appears, nor 'meta tag', 'mojibake', or file extensions like .html/.tsx.

Distinctiveness Conflict Risk

The rule topic (UTF-8 charset declaration) is a clear niche, but the trigger boilerplate 'Use when reviewing templates, rendered HTML, or shared components related to…' would be shared verbatim by any sibling HTML-rule skill, leaving only the rule title to disambiguate. Mostly distinct with minor overlap risk against closely related skills — anchor 4, not 5.