Conciseness

The body is dense and free of padding or explanations of known concepts, but at least four rules are stated two or three times: "Print the rule violated and the sanctioned alternative" (§3) reappears as "No silent blocks: Print the rule and the allowed alternative", "Paired with a skill" returns as "No guardrail without a skill", the Priority statement returns as "No prompt-only rules", and §4's test-lock rules are restated in Red Flags. This matches anchor 3 ("mostly efficient... could be tightened") rather than 4, where duplication would be only minor trim instances.

Actionability

Guidance is directly executable for an instruction-only skill: concrete decision semantics ("Exit 0: allow", "Exit 2: block... on stderr", "fail closed on production classes"), specific deny patterns (".env*, .ssh/, credentials*.json|yaml"), named logging fields ("timestamp, rule, tool, target, and outcome"), and a copy-paste-ready policy skeleton in references/guardrails-template.yaml with per-field comments. Common cases are covered by the class table and host-mapping reference; no gaps remain.

Workflow Clarity

The test-lock flow is sequenced with an explicit verification gate ("Unlock only when the fix is verified") and Red Flags provide recovery loops ("Stop if the fix edits the failing test: Restore the test and fix the production code"), with fail-closed semantics as a checkpoint for unevaluable cases. It is not a 5 because the overall policy-authoring process is implicit across sections rather than an explicit end-to-end sequence, and how the fix is verified before unlocking the test lock is unspecified.

Progressive Disclosure

SKILL.md is a lean overview with clearly signaled references — all three linked files (guardrails-template.yaml, runtime-adapters.md, untrusted-workspace-admission.md) exist and each is annotated with its purpose. It is not a 5 because the reference layer chains onward: runtime-adapters.md and untrusted-workspace-admission.md cross-link each other and point to ../../common-llm-security/SKILL.md and ../../common-security-audit/references/trust-review-policy.md, which do not resolve within this bundle, making effective depth two-plus levels from the entry point.

Specificity

The description enumerates five concrete capabilities — "protected paths, test-file locks during bug fixes, post-edit formatters, production approval gates, secret deny rules" — matching the full guardrail class table in the body, so coverage is comprehensive with no gaps. It is not a 4 because the action list has no minor coverage gaps, and voice is third person ("Define..."), so no voice penalty applies.

Completeness

Both halves are explicit: the "what" ("Define deterministic guardrails for agent tool calls — protected paths, test-file locks...") and the "when" ("Use when writing or reviewing a hook policy, or moving an always-do-X rule out of prose into enforcement") with concrete trigger phrases. This matches the anchor-5 pattern exactly; a 4 would require the when-clause to be weaker or less explicit.

Trigger Term Quality

Good natural keyword coverage — "guardrails", "hook policy", "protected paths", "approval gate", "secret deny" — but common variations a user would actually say ("hooks", "PreToolUse", "block edits", "settings.json") appear only in the metadata triggers, not the description itself. This matches anchor 4 ("good keyword coverage; a few natural terms missing") and falls short of anchor 5's comprehensive synonyms and file extensions.

Distinctiveness Conflict Risk

The niche — converting always-hold rules into deterministic hook enforcement — is clear and the trigger "moving an always-do-X rule out of prose into enforcement" is distinctive. However "writing or reviewing a hook policy" is broad enough to overlap with general hook-configuration or security-review skills, matching anchor 4 ("mostly distinct; minor overlap risk with closely related skills") rather than the minimal-conflict anchor 5.