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authentication

How auth works in agent-native apps. Use when wiring login/signup, configuring auth modes, setting up organizations, protecting routes, or debugging session issues.

Quality

72%

Does it follow best practices?

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SecuritybySnyk

Passed

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tessl review fix ./.agents/skills/authentication/SKILL.md
SKILL.md
Quality
Evals
Security

Quality

Content

63%Weight 40%Scale 1-5

Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.

A highly actionable, project-specific reference with concrete code, exact env vars, and well-signaled invariants, hurt mainly by its monolithic length: major topic areas are inlined in SKILL.md instead of being split into one-level-deep reference files. The Cross-App SSO/Desktop SSO material in particular duplicates detail that its own pointer says lives in /docs/cross-app-sso.

Suggestions

Split the Cross-App SSO, Packaged Desktop SSO, Org Service Principals, and A2A Identity sections into reference files (e.g., references/cross-app-sso.md, references/service-principals.md) and keep only a short summary plus a clearly signaled link in SKILL.md.

Tighten the long prose paragraphs in Remote MCP OAuth and the auth-modes table into shorter rule statements; much of the token-semantics detail can move to a reference file.

Add explicit validation feedback loops (e.g., run `guard:ssr-cache-shell` / the relevant spec after changing SSR behavior) as numbered steps in the sections that prescribe risky changes, rather than only naming the guards inline.

DimensionReasoningScore

Conciseness

The body is dense with project-specific invariants and avoids general-knowledge padding, but at ~420 lines it contains very long prose paragraphs (Remote MCP OAuth, Cross-App SSO, Packaged Desktop SSO) that could be substantially tightened or trimmed.

3 / 5

Actionability

Concrete, executable guidance throughout: complete `getSession(event)` handler code, a `defineAppRoles` snippet, the sign-in `return` redirect code, `AppProviders` JSX, exact env vars, file paths, and endpoints. Some sections (SSO, A2A identity, Desktop SSO) give rules as prose only, with no code or commands.

4 / 5

Workflow Clarity

Sequences are clearly laid out with checkpoints: the canary rollout runbook (Off → verify → enable for one test email/org → verify → expand), enforcement via guard scripts (`guard-no-localhost-fallback.mjs`, `guard:ssr-cache-shell`) and spec files, and the stop-and-confirm rule before org migration. Most tasks lack an explicit validate→fix→retry loop, keeping it below 5.

4 / 5

Progressive Disclosure

Good `##` section structure and pointers to other skills and docs (`security`, `actions`, `/docs/cross-app-sso`), but no bundle files exist at all: the entire ~420-line body is one file, and sections like Cross-App SSO, Desktop SSO, Org Service Principals, and A2A Identity clearly belong in separate reference files — the `/docs/cross-app-sso` pointer is buried at the end of a section that already inlines the full detail.

3 / 5

Total

14

/

20

Passed

Description

75%Weight 40%Scale 1-5

Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.

A well-formed description with an explicit and appropriately detailed "Use when…" trigger clause covering several concrete tasks. Its main weakness is a topic-level rather than action-level capability statement and omission of significant covered domains (SSO, OAuth, service tokens) from the triggers.

Suggestions

Add SSO, OAuth, and sign-in/log-in synonyms to the trigger clause so users asking about those topics surface this skill.

Make the "what" statement action-oriented (e.g., "Wires login/signup, configures auth modes and organizations, protects routes, and debugs sessions in agent-native apps") instead of the topic-level "How auth works".

DimensionReasoningScore

Specificity

The trigger clause enumerates several specific concrete tasks ("wiring login/signup, configuring auth modes, setting up organizations, protecting routes, or debugging session issues"), but the capability statement itself is topic-level ("How auth works in agent-native apps") rather than action-based, and SSO/OAuth/MCP-token work the body covers is not mentioned.

4 / 5

Completeness

Both halves are present: a clear "what" ("How auth works in agent-native apps") and an explicit "Use when…" clause with five concrete triggers. Not a 5 because the "what" is a topic statement rather than the concrete action list the top anchor requires.

4 / 5

Trigger Term Quality

Natural keywords users would say are present ("login", "signup", "session", "organizations", "routes"), but common synonyms like "sign-in", "log in", "SSO", "OAuth", and "tokens" are missing even though the body covers them heavily.

4 / 5

Distinctiveness Conflict Risk

"agent-native apps" scopes a clear auth niche with distinct triggers (login, session, auth modes), but "setting up organizations" and "protecting routes" mildly overlap adjacent skills (security, actions, org/team) that the body itself cross-references.

4 / 5

Total

16

/

20

Passed

Validation

68%

Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.

Validation — 11 / 16 Passed

Validation for skill structure

CriteriaDescriptionResult

metadata_version

'metadata.version' is missing

Warning

metadata_field

'metadata' should map string keys to string values

Warning

frontmatter_unknown_keys

Unknown frontmatter key(s) found; consider removing or moving to metadata

Warning

relative_links

Relative link issues: 2 suspicious

Warning

referenced_paths_exist

Referenced path issues: 3 missing

Warning

Total

11

/

16

Passed

Repository

BuilderIO/agent-native

Path

.agents/skills/authentication/SKILL.md

Reviewed

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