Conciseness

The body is dense with executable commands and assumes AWS knowledge rather than explaining concepts, but contains minor trimmable redundancy: the Overview restates the description, the hardcoded-credentials warning appears in both Parameters ("hardcoded demo authorization values... NOT suitable for production") and Security Considerations, and the repeated "You MUST" constraint framing pads each step. It matches the score-4 anchor (efficient, minor over-explanation) rather than score 5 (every token earns its place).

Actionability

Nearly every step gives copy-paste-ready AWS CLI commands (create-role, create-function, create-domain-name, the curl test, validate.sh), matching the score-5 anchor's executability. It drops to 4 because a few MUST constraints lack any command — "MUST support multiple input methods (direct input, file path, URL)" and "MUST configure request validation to reject malformed query parameters... by validating that QueryString1 and HeaderAuth1 match expected patterns" give no concrete implementation — the minor-gaps case of score 4.

Workflow Clarity

Ten explicitly ordered steps with sequencing guards ("This step MUST be performed before all other steps", "MUST NOT create the deployment until all resources, methods, and integrations are configured"), validation checkpoints at each stage (wait certificate-validated, 10-second IAM propagation wait, get-function/get-stage/get-domain-name verification, final validate.sh), and feedback loops in Troubleshooting (e.g., retry the ACM wait when PENDING_VALIDATION, diagnose 401/403 causes). This matches the score-5 anchor with explicit validation and error-recovery guidance.

Progressive Disclosure

All five bundle files referenced in the body (scripts/lambda-trust-policy.json, authorizer.mjs, example_function.mjs, dns-record.json, validate.sh) exist exactly one level deep and are clearly signaled with their purpose, and sections (Parameters, Steps, Examples, Troubleshooting, Security) are well organized. It falls short of score 5 because the entire command-heavy procedure — including the very long inline CLI invocations and log-format strings — is inlined in SKILL.md rather than split out, a minor organization gap consistent with the score-4 anchor.

Specificity

The description enumerates seven concrete actions — "ACM certificate provisioning, API Gateway REST API creation, Lambda function deployment, request authorizer setup, custom domain configuration, base path mapping, and Route 53 DNS record creation" — which comprehensively covers the deployment pipeline. It clearly matches the score-5 anchor (multiple specific concrete actions, comprehensive) and exceeds the score-4 anchor, which allows coverage gaps.

Completeness

It explicitly answers "what" (the enumerated deployment actions) and "when" via the explicit trigger clause "Trigger keywords: custom domain, REST API, Lambda, Route 53...". This is equivalent explicit trigger guidance per the judging guidelines, matching the score-5 anchor with concrete trigger phrases; it is not score 4, which requires the 'when' to be less explicit.

Trigger Term Quality

The trigger list includes natural terms users would say: "custom domain, REST API, Lambda, Route 53, API Gateway, regional endpoint, request authorizer, base path mapping" — good coverage. It falls short of the score-5 anchor because a few natural variations are missing (e.g., "DNS record", "domain name", "API endpoint"), but it is well above score 3, which requires missing common terms.

Distinctiveness Conflict Risk

The combination of "Regional REST API", "request-based Lambda authorizer", and "base path mapping" carves out a clear AWS API Gateway niche with distinct triggers and minimal conflict risk. It matches the score-5 anchor; score 4 would imply meaningful overlap with closely related skills, which is not the case.