Content
78%Weight 40%Scale 1-5Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.
A well-structured, highly actionable skill body: executable code for every common AuthenticationServices flow, explicit per-state and per-error handling, appropriate offloading of deep passkey and Keychain/biometric patterns to real one-level-deep reference files, and a review checklist for validation. Remaining weaknesses are minor: some duplication between the credential table, code comments, and checklist, a few placeholder helper functions, and no guidance for server-side validation failure recovery.
Suggestions
Merge the Credential Handling table into the delegate code comments (or vice versa) so each fact appears once; the identity-token/password storage points are also repeated in Common Mistakes and the Review Checklist.
Add a short failure-recovery note to Token Validation, e.g., what the client should do when the server rejects the identityToken or authCode exchange (retry, re-authenticate, force sign-in).
Either show a minimal Keychain-based implementation of saveUserID/loadSavedUserID or note explicitly that they are the app-specific seam defined in references/keychain-biometric.md, so the inline code path is fully traceable.
| Dimension | Reasoning | Score |
|---|---|---|
Conciseness | The body is dense with non-obvious, API-specific facts Claude cannot be assumed to know ("nil after first authorization", credentialRevokedNotification, the JWKS URL and iss/aud/exp checks, the NSFaceIDUsageDescription crash, .preferImmediatelyAvailableCredentials) with no concept-teaching padding. It falls short of the score-5 anchor because the Credential Handling table largely restates the delegate code comments and the Review Checklist repeats several earlier points, so a little redundancy could be trimmed. | 4 / 5 |
Actionability | Mostly executable: complete Swift for the SIWA controller setup, delegate success/failure handling, credential-state switch, revocation observer, existing-account setup, and the ASWebAuthenticationSession OAuth flow, plus specific one-liners like textContentType assignments. Minor gaps keep it below score 5: helper calls such as saveUserID and exchangeCodeForTokens are unimplemented placeholders, and the SwiftUI SignInWithAppleButton and passkey sections are prose-only, deferring code to the reference files. | 4 / 5 |
Workflow Clarity | The launch sequence is clear and checkpointed: performExistingAccountSetupFlows runs before showing login UI with explicit ".notInteractive" silent-fallback handling, the credential-state switch spells out an action for every state (authorized/revoked/notFound/transferred/@unknown default), and the error delegate enumerates .canceled, .failed, and .notInteractive. It misses score 5 because there is no explicit feedback loop for server-side outcomes, e.g., what to do when identity-token validation fails on the server. | 4 / 5 |
Progressive Disclosure | Structure matches the score-5 anchor: a Contents TOC aids navigation, both bundle files exist and are well-signaled with their contents described ("Load references/passkeys.md for the canonical registration, assertion, result handling, AutoFill-assisted, and physical security-key flows"; "See references/keychain-biometric.md for the canonical LAContext, fallback, SecAccessControl, and .biometryCurrentSet patterns"), references are one level deep, and the split is appropriate — core flows inline, deep patterns in the two reference files. | 5 / 5 |
Total | 17 / 20 Passed |