Conciseness

The body is dense with executable commands and tables and never explains background concepts Claude already knows, fitting anchor 4's "efficient; minor instances of over-explanation". It is not 5 because of repeated "Per [sf-gh][sf-gh]" attribution phrases, a meta-framing paragraph in Step 6, and inline time-sensitive pins (e.g. `anchore/scan-action@v0`, `grype-db-v6-2026-05-06.tar.gz`, "in effect 2024+") that the rubric says to penalize when not in a deprecated section.

Actionability

Every step ships copy-paste-ready material: install commands, `syft <image> -o spdx-json=./spdx.json -o cyclonedx-json=./cdx.json` multi-format output, cosign attest/verify, `grype sbom:./sbom.json --fail-on high --only-fixed` gates, a jq-based CI gate script, and complete GitHub Actions YAML. This matches anchor 5's fully executable, common-case-covering standard.

Workflow Clarity

Steps 1-10 are clearly sequenced and cross-referenced with explicit checkpoints (Step 6 inventory-accuracy diff, severity CI gate, quarterly ignore-rule audits, baseline rotation only on a clean diff), fitting anchor 4. It sits between 4 and 5 because the fix-and-retry recovery loops for gate failures are distributed across referenced files rather than presented as explicit inline loops as anchor 5 requires.

Progressive Disclosure

The spine keeps common usage inline and links four real, well-described reference files one level deep (formats, grype-ignore-rules, diff-ci-workflows, sbom-formats), matching anchor 4's good structure. It is not 5 because three bundle files (spdx.md, component-types-and-tooling.md, spdx3-profiles-and-tooling.md) are reachable only via a second hop through sbom-formats.md, slightly beyond the one-level-deep ideal; the nesting is clearly signaled so it does not fall to lower anchors.

Specificity

"Generates CycloneDX or SPDX SBOMs with Syft, scans them with Grype, diffs SBOMs in CI and explains how to choose a format" lists four concrete actions spanning generation, scanning, diffing, and format selection. Coverage is comprehensive across the skill's capabilities, matching the anchor-5 example rather than the minor-gaps anchor at 4.

Completeness

Explicitly answers both questions: the trigger clause "Use for any question or task about SBOMs, including generating one for a container image or folder..." gives concrete when-phrases, and the what is stated as concrete tool actions. This matches the anchor-5 example with explicit what and when plus concrete trigger phrases.

Trigger Term Quality

Strong natural keywords: "SBOM", "container image", "vulnerability scanning", "release job", "drift between releases", "CycloneDX", "SPDX", "Syft". It falls short of anchor 5 because natural synonyms like "software bill of materials" or "supply chain" are absent, but keyword coverage clearly exceeds anchor 3's partial coverage.

Distinctiveness Conflict Risk

The SBOM/Syft niche is clear and distinct, but the "vulnerability scanning" trigger overlaps with closely related scanning skills (trivy, OSV-Scanner, and Snyk workflows are sister tools per the body). Minor overlap risk with closely related skills fits anchor 4; anchor 5's minimal-conflict standard is not met.