Conciseness

The body is efficient: terse tables for SCM options and troubleshooting, exact commands, no explanation of concepts Claude already knows, and every section maps to a decision or artifact. Not a 5 because the Reconfiguration section partially restates behavior already embedded in Steps 3–4 (existing-file detection), and "Follow these steps in exact order. Do NOT skip steps or reorder them." plus the inline script comments add a little trimmable padding.

Actionability

Fully executable throughout: copy-paste bash for prerequisite checks, auth.json creation, cosign key generation, and scs.env; a complete, runnable hook script with concrete substitution placeholders ({{COMMAND_FILTER}}, {{URL_REGEX}}, {{KEY_PATH}}); and an exact JSON merge target for settings.json. The SCM table gives literal command_filter and url_pattern values per platform, covering the common cases.

Workflow Clarity

Six explicitly ordered steps with sequencing enforcement ("Do NOT skip steps or reorder them"), a hard gate at Step 1 ("Do not proceed until all are installed"), validation of existing state in Step 3 (jq -e check of token and account_id) and Step 4 (key readable, password-protected warning), an idempotency requirement for the settings.json patch, a post-setup verification instruction, and a Troubleshooting table that closes the loop on failure symptoms. This is not a destructive/batch operation, and the reconfiguration path still requires confirmation ("Never silently overwrite").

Progressive Disclosure

No bundle files exist, and the single SKILL.md is well organized into Instructions, Troubleshooting, Reconfiguration, and Limitations sections with no nested references. Not a 5 because at ~235 lines the bulk inline content — particularly the ~55-line hook script template and the SCM regex table — would sit more appropriately in a scripts/ or references/ file, keeping the body as an overview.

Specificity

Lists several concrete actions — "set up PR attestation", "install harness-scs attestation hook", "configure agent attestor", "troubleshoot why agent attestation isn't uploading", "reconfigure an existing attestation hook" — covering install, configure, troubleshoot, and reconfigure paths. Not a 5 because the actions largely restate the trigger verbs and the concrete outcome (signed in-toto attestation uploaded to the Harness Evidence Vault) is never stated in the description itself.

Completeness

"Use when asked to..." plus the explicit trigger list answers "when" maximally, and the "what" is explicitly present in the action verbs (set up / install / configure attestation tooling). Not a 5 because there is no explicit capability statement of what the skill produces (the in-toto attestation hook for the Evidence Vault lives only in metadata.summary, not the description); not a 3 because "what" is more than weakly implied — the actions themselves are stated.

Trigger Term Quality

The dedicated trigger-phrase list comprehensively covers natural phrasings and synonyms: "set up PR attestation", "set up agent attestation", "configure agent attestor", "configure PR signing", "install attestation hook", "configure claude attestation", and the colloquial troubleshooting phrase "why isn't my agent attestation uploading". These are exactly what a user would say; no natural variation is obviously missing.

Distinctiveness Conflict Risk

Anchored on highly specific terms — "harness-scs attestation hook", "agent attestor", "cosign key", "Harness identity" — giving it a clear niche with distinct triggers and minimal overlap risk with generic CI/CD or git skills.