Conciseness

The body is dense directive prose that assumes competence — it names exact functions (`normalizeSecurityMetadata`, `util.FindReplace`, `cfgutil.EncodeArgs`), exact paths, and exact test names with no basic-concept padding. Minor over-explanation exists (the Repository Scope boundary rules are restated across several paragraphs), keeping it at anchor 4 rather than the uniformly lean anchor 5.

Actionability

Guidance is fully concrete and executable for an instruction-only skill: the parser signature `func parseCaddyfileSurface(d *caddyfile.Dispenser, cfg *authcrunch.Config) error`, specific helpers (`d.RemainingArgs()`, `d.ArgErr()`, `h.Errf`), exact fixture paths (`testdata/caddyfile_adapt/` with `<prefix>.Caddyfile`, expected `<prefix>.json`), named tests (`TestResolveRuntimeAppConfig`, `TestAuthzResponseContract`), and commands (`gofmt`, `make license`). Anchor 5's copy-paste-ready specificity is met via these exact identifiers and contracts.

Workflow Clarity

Sequences are present with most checkpoints: "Before a mutating command, confirm its repository root and working directory, inspect the invoked script's side effects, and resolve its output paths" is an explicit validation gate for risky sibling-repository operations, and the Acceptance criteria section plus the change-based test-selection workflow provide verification endpoints. It falls short of anchor 5 because the workflow is distributed across sections rather than given as one ordered procedure with feedback loops.

Progressive Disclosure

Both bundle references exist and are one level deep, each clearly signaled with a purpose statement and a 'read when' trigger ("read [Runtime lifecycle](references/runtime-lifecycle.md). It traces Caddy's host ordering..." and "[Host plugin contracts](references/host-plugins.md). It defines module naming..."). Detailed material is appropriately split into these files (318 and 389 lines) while the SKILL.md keeps directive-level content, matching anchor 5's clear overview with well-signaled references.

Specificity

"Implement or review caddy-security Go code, Caddy modules, parsers, lifecycle, and HTTP delegation" names the domain precisely and enumerates several concrete technical areas (modules, parsers, lifecycle, HTTP delegation, errors, logging, conventions), though the action verbs are limited to implement/review. This sits above anchor 3 (only 1-2 concrete actions, not comprehensive) but the restricted verb set keeps it below anchor 5's multiple distinct concrete actions.

Completeness

The 'what' is explicit ("Implement or review caddy-security Go code, Caddy modules, parsers, lifecycle, and HTTP delegation") and the 'when' is an explicit "Use for" clause with concrete trigger phrases ("app/plugin boundaries, authcrunch integration, errors, logging, and code conventions"). This clearly matches anchor 5; anchor 4 would require the 'when' to be less explicit or specific, which it is not.

Trigger Term Quality

Triggers like "Caddy modules", "parsers", "lifecycle", "HTTP delegation", "authcrunch integration", "errors, logging, and code conventions" are natural phrasing for users of this codebase. A few natural terms are missing (e.g., "Caddyfile", "directives", "middleware"), matching anchor 4 (good keyword coverage, a few natural terms missing) rather than anchor 5's synonym/extension completeness.

Distinctiveness Conflict Risk

"caddy-security" plus "Caddy modules, parsers, lifecycle" carves out a clear coding-directives niche distinct from sibling configuration/testing skills, with minimal conflict risk. It is not the anchor-4 case of overlapping broadly related skills — the repo-scoped triggers are unambiguous.