Conciseness

The body teaches nothing Claude already knows and is tightly written ('Read-only APIs only', 'Verify, don't guess', 'Match the user's language'), but the evidence-state taxonomy is defined twice ('UNKNOWN for denied, partial, stale or missing evidence; NOT ASSESSED for an intentionally unrun check' appears in 'Routing and file delivery' and again nearly verbatim in 'Focused recommendations') and the no-scan/no-suppression rules repeat across Global rules 1 and 3 and the implementation-handoff bullet. This is more than the 5 anchor's 'every token earns its place' but only minor trimming, so it sits above the 3 anchor's 'some unnecessary explanation'.

Actionability

Concrete dispatch throughout: exact paths in two routing tables ('references/guardduty-configuration.md', 'references/service-recommendations/inventory-commands.md'), an exact tool invocation ('Pass its path to retrieve_skill(skill_name="aws-security", file="references/...")'), and specific checks ('aws:SourceArn and aws:SourceAccount condition keys'). Not 5 because the executable API commands and per-procedure steps are delegated to references and several statements remain abstract policy ('These priorities are workflow-authored, not observed findings severity or guide-assigned ratings').

Workflow Clarity

The sequence is explicit ('The recommendation workflow runs in three passes: inventory, then read-only enablement checks, then the inventory-to-service recommendation matrix') with pre-flight checkpoints ('Before authorized live reads, verify identity, selected profile, accounts, regions and relevant organization role') and uncertainty gating ('UNKNOWN and NOT ASSESSED are never gaps'), so well above the 3 anchor. Not 5 because recovery behavior after a failed checkpoint (e.g. a denied scope verification) is not stated and the per-pass steps live in the references rather than the body.

Progressive Disclosure

The body is a lean overview with two well-signaled routing tables mapping intent to exact file paths, all of which exist in the bundle (24 files in references/ plus 12 under references/service-recommendations/, including the 39KB enablement-checks.md and 27KB recommendation-matrix.md kept out of the overview). It adds a guardrail resolving paths for MCP vs local installs, lazy-load guidance ('Read only the domain relevant to the decision; follow additional links only for a necessary prerequisite'), and missing-file handling ('Report missing references before giving dependent guidance') — everything is one hop from SKILL.md with easy navigation.

Specificity

The description enumerates concrete capability areas across the whole AWS security catalog: 'WAF/origin overlap, AWS Network Firewall inspection coverage and policy review, VPC endpoint, Transit Gateway/Cloud WAN segmentation and DNS Firewall security-control suitability, certificate renewal ownership and monitoring, incident response triage ownership, centralized security log store (CloudWatch or Security Lake)' plus 'factual configuration, findings, data sources and severity scoring for GuardDuty, Inspector, Security Hub V2/OCSF (Exposure, connectors, automation), Security Hub CSPM/ASFF (standards, controls), Macie, Detective, Security Lake'. Coverage spans both advisory and factual deliverables with no evident gaps, matching the 5 anchor rather than the 4 anchor's 'minor gaps'.

Completeness

What is explicit ('AWS security service suitability, coverage and cost recommendations... factual configuration, findings, data sources and severity scoring') and when is explicit and equivalent to a 'Use when...' clause ('Applies to advisory security-service choices even when one service is named'), reinforced by negative scope ('Implementation, rule or code authoring, deployment, scans and troubleshooting outside these factual procedures belong to specialist skills'). The when-clause includes a concrete disambiguating condition (single-service advice), so it exceeds the 4 anchor where 'when' could still be more specific.

Trigger Term Quality

Natural vocabulary is comprehensive on service names and decision words users actually say: 'GuardDuty, Inspector, Security Hub V2/OCSF', 'WAF', 'VPC endpoint, Transit Gateway/Cloud WAN segmentation and DNS Firewall', 'certificate renewal', 'coverage and cost recommendations'. A few natural generic terms are absent ('compliance', 'vulnerability', 'security review/audit'), which fits the 4 anchor ('a few natural terms missing') rather than the 5 anchor's full synonym coverage; 'scans' is deliberately excluded from scope so its absence is correct scoping, not a gap.

Distinctiveness Conflict Risk

Triggers are AWS-security-service-specific ('GuardDuty', 'AWS Network Firewall', 'Security Hub V2/OCSF', 'centralized security log store (CloudWatch or Security Lake)') and the description actively disambiguates against neighboring skills by routing implementation, rule/code authoring, deployment, scans and troubleshooting to 'specialist skills'. This is a clear niche with distinct triggers and minimal conflict risk, matching the 5 anchor.