Conciseness

Lean throughout: it assumes Claude knows Terraform and the Plugin Framework, and spends its tokens only on non-obvious ephemeral semantics (renew cannot return a new result, Private bytes forwarding, no state) and executable code rather than padding or introductory concept explanation.

Actionability

Provides complete, copy-paste-ready Go covering Metadata, Schema, Open, Renew, Close, type assertions, and EphemeralResources() registration, plus concrete Design Rules (Sensitive: true, RenewAt margin, skip Close if not revocable) that are directly applicable.

Workflow Clarity

Clear sequenced sections (When to Use → Lifecycle → Implementation → Registration → Design Rules → Testing → Documentation) culminating in an explicit Checklist, with the Testing section providing validation guidance (echo-provider tests, version gating) for verifying the result.

Progressive Disclosure

Well-organized into clearly headed sections with appropriately signaled one-level references (sibling skills 'if available', official docs link), but the skill is fully self-contained with no bundle files, so there is no progressive file split to navigate — slightly below the anchor that emphasizes appropriately split content.

Specificity

Lists multiple concrete actions — 'the Open/Renew/Close lifecycle, ephemeral schema design, registration via EphemeralResources, renewal for expiring credentials, and how ephemeral values flow into write-only attributes and provider configuration' — giving comprehensive coverage rather than vague abstraction.

Completeness

Explicitly answers both 'what' (implement lifecycle/schema/registration/renewal/value flow) and 'when' ('Use when adding an ephemeral resource, exposing secrets... deciding between an ephemeral resource and a data source, or wiring short-lived credentials') with concrete trigger phrases.

Trigger Term Quality

Natural phrases users would say are present with synonyms — 'adding an ephemeral resource', 'exposing secrets/tokens/certificates that must never persist in state or plan', 'wiring short-lived credentials from one provider into another' — covering the common ways this need is expressed.

Distinctiveness Conflict Risk

Occupies a clear niche (Terraform Plugin Framework ephemeral resources) with triggers specific enough — ephemeral vs data source, write-only attributes, short-lived credentials — to avoid firing for unrelated provider skills.