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vercel-flags

Feature flags, A/B tests, and gradual rollouts with Vercel Flags, in any app or framework. Use whenever the user is planning, adding, or changing a feature flag, toggle, kill switch, experiment, percentage rollout, or targeting rule, or wants to gate or hide a feature for some users, even before a library or provider is chosen. Covers choosing an integration (Flags SDK, `@vercel/flags-core`, OpenFeature), the Vercel dashboard, the `vercel flags` CLI (create, inspect, set, split, rollout, rules, segments, evaluations, archive), OIDC vs SDK keys, `FLAGS_SECRET`, and Flags Explorer overrides. For `flag()` declarations, adapters, precompute, and the Flags Explorer endpoint in Next.js or SvelteKit code, load the `flags-sdk` skill.

78

Quality

98%

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SKILL.md
Quality
Evals
Security

Quality

Content

100%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 tightly written, high-signal skill body: it routes requests decisively, gives concrete CLI commands and a complete code example, builds validation into every flow (inspect-first, verify-evaluations-before-archive), and pushes depth into a single well-signaled reference file. Nothing explains concepts Claude already knows, and every caveat is an operational gotcha specific to Vercel Flags.

DimensionReasoningScore

Conciseness

The body is dense and prescriptive with essentially no padding: it never explains what a feature flag is, and every sentence carries non-obvious, domain-specific gotchas (e.g. "With OIDC the token can come from request context and may not exist during module loading... local `.env.local` credentials can hide this timing problem", "a `.vercel/` directory alone does not prove a link"). It assumes Claude's competence throughout; not score 4 because no section reads as over-explanation that could be trimmed.

5 / 5

Actionability

Concrete, executable guidance throughout: exact commands (`vercel flags create <key> --kind boolean --description "<description>"`, `rollout <key> --by user.id ...`, `vercel project inspect --non-interactive`, `--project`/`--scope`), a complete copy-paste TypeScript example for `@vercel/flags-core`, and an explicit instruction to run `vercel flags <cmd> --help` before unshown subcommands rather than guessing. The common flows (create, enable/set, rollout, split, verify, retire) each have a concrete command form.

5 / 5

Workflow Clarity

The request-routing section gives an unambiguous decision tree (planning vs. CLI-only vs. existing SDK vs. other provider), "Plan a flag" is a pre-creation checklist, and validation checkpoints are explicit: "Always `inspect` first so you know what each environment serves today", "remove the code first, verify no evaluations, then `archive`; `rm` only for archived flags", plus error-recovery guidance ("If the CLI rejects `--project`, upgrade it first"; `link_required` handling; "stop and ask instead of relinking"). The destructive/batch cap at 3 does not apply because validation before archiving/deleting is present.

5 / 5

Progressive Disclosure

The body is an overview/router that delegates deep CLI-concept mapping and the safety checklist to a single, one-level-deep reference (`references/cli.md`), which exists and contains the cited "Lifecycle and safety" anchor. The reference is clearly signaled both inline and in a dedicated References section with a description of its contents; the only inline code is the short, necessary `@vercel/flags-core` example.

5 / 5

Total

20

/

20

Passed

Description

100%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 model description: concrete and comprehensive on actions, rich in natural trigger phrases with synonyms, explicit on both what and when, and clearly distinguished from the sibling flags-sdk skill. It avoids fluff and over-claiming while covering planning, management, rollouts, credentials, and retirement.

DimensionReasoningScore

Specificity

The description enumerates concrete actions across the full lifecycle — "planning, adding, or changing a feature flag", "gate or hide a feature", and specific CLI verbs "create, inspect, set, split, rollout, rules, segments, evaluations, archive" — plus concrete artifacts (Flags SDK, `@vercel/flags-core`, OpenFeature, OIDC, `FLAGS_SECRET`). Coverage is comprehensive with no vague filler, and it is written in third person ("Covers choosing an integration").

5 / 5

Completeness

It explicitly answers both questions: "what" ("Feature flags, A/B tests, and gradual rollouts with Vercel Flags... Covers choosing an integration... the `vercel flags` CLI...") and "when" ("Use whenever the user is planning, adding, or changing a feature flag, toggle, kill switch, experiment, percentage rollout, or targeting rule, or wants to gate or hide a feature for some users"). The trigger guidance is explicit and concrete, matching the top anchor.

5 / 5

Trigger Term Quality

It includes the natural phrases users actually say — "feature flag", "toggle", "kill switch", "experiment", "percentage rollout", "targeting rule", "gate or hide a feature", "A/B tests", "gradual rollouts" — with synonyms covered (flag/toggle, experiment/A-B test). Not below 5 because no common variation is missing; not above because 5 is the scale maximum.

5 / 5

Distinctiveness Conflict Risk

It occupies a clear niche (Vercel's feature flags platform) and explicitly disambiguates against the closest overlapping skill: "For `flag()` declarations, adapters, precompute, and the Flags Explorer endpoint in Next.js or SvelteKit code, load the `flags-sdk` skill." Named platform artifacts (`@vercel/flags-core`, `FLAGS_SECRET`) further reduce mis-trigger risk.

5 / 5

Total

20

/

20

Passed

Validation

81%

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

Validation — 13 / 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

Total

13

/

16

Passed

Repository

vercel/vercel-plugin

Path

skills/vercel-flags/SKILL.md

Reviewed

Table of Contents

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