The body is terse and bullet-driven, names exact functions/constants/hooks without explaining what WordPress or REST is, and defers detail to reference files; every line earns its place.

Gives concrete, specific guidance — an executable triage command, exact WP functions (register_rest_route, rest_ensure_response, WP_Error), constants (WP_REST_Server::READABLE/CREATABLE/EDITABLE/DELETABLE), and parameters (?context=edit, _fields=content.raw); for an instruction-only skill this is fully actionable.

A clearly numbered Procedure (0–6) is paired with an explicit Verification checklist (/wp-json/ index, OPTIONS schema, 401/403 behavior, run lint/tests/build) and a Failure modes/debugging section that supplies error-recovery feedback loops.

SKILL.md acts as a concise overview with clearly signaled, one-level-deep references (e.g. "Read references/routes-and-endpoints.md and references/schema.md"); all six reference files exist and are flat summaries with no nested references.

Lists many concrete actions and primitives — "register_rest_route, WP_REST_Controller/controller classes, schema/argument validation, permission_callback/authentication, response shaping, register_rest_field/register_meta, ... exposing CPTs/taxonomies via show_in_rest" — rather than vague language.

Opens with an explicit "Use when ..." trigger clause and follows it with a concrete enumeration of what the skill covers, answering both when and what clearly.

Combines natural user phrasing ("building, extending, or debugging WordPress REST API endpoints/routes") with the exact technical terms a developer would say (register_rest_route, permission_callback, register_meta, show_in_rest), giving broad coverage.

Scoped tightly to the WordPress REST API with distinctive triggers (WP_REST_Controller, show_in_rest, register_rest_field) that are unlikely to fire for unrelated skills.