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flags

How to add or modify Next.js experimental feature flags end-to-end. Use when editing config-shared.ts, config-schema.ts, define-env-plugin.ts, next-server.ts, export/worker.ts, or module.compiled.js. Covers type declaration, zod schema, build-time injection, runtime env plumbing, and the decision between runtime env-var branching vs separate bundle variants.

Quality

90%

Does it follow best practices?

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SKILL.md
Quality
Evals
Security

Quality

Content

86%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 lean, well-structured internal skill that delivers dense actionable wiring guidance without over-explaining basics. Adding a brief inline verification step and one concrete code example per approach would lift actionability and workflow clarity further.

Suggestions

Add an inline verification checkpoint (e.g., 'confirm the flag is replaced at build time and read as an env var at runtime') rather than relying solely on the $runtime-debug related skill.

Include a small copy-paste code snippet for the zod schema addition and the DefinePlugin entry to make the guidance fully executable.

Show the NextConfigRuntime Pick type addition with a one-line type example so the runtime-flag step is unambiguous.

DimensionReasoningScore

Conciseness

Dense, reference-style body that assumes Claude knows Next.js internals — no padding explaining what a flag or a bundle is — where every bullet ('define-env.ts affects user bundling, not pre-compiled runtime internals') earns its place.

5 / 5

Actionability

Highly actionable instruction-style guidance naming exact files and selectors ('Set in next-server.ts + export/worker.ts', 'scoped to bundleType === "app"'), but lacks copy-paste code snippets for the zod schema or DefinePlugin entry shape.

4 / 5

Workflow Clarity

Clear sequenced wiring ('config-shared.ts (type) → config-schema.ts (zod)') with explicit conditional branching for bundled vs runtime consumers; validation is only implied (delegated to the $runtime-debug related skill) rather than stated inline.

4 / 5

Progressive Disclosure

Under 50 lines, single-purpose, and well-organized into clearly labeled sections (Required Wiring, Where the Flag Is Consumed, Runtime-Bundle Model, Related Skills) with no external references needed.

5 / 5

Total

18

/

20

Passed

Description

92%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 strong, specific description that clearly states the capability and provides concrete file-based triggers. Minor room to add synonyms such as 'feature toggle' for broader trigger coverage.

DimensionReasoningScore

Specificity

Lists multiple concrete actions covering the end-to-end wiring — 'type declaration, zod schema, build-time injection, runtime env plumbing, and the decision between runtime env-var branching vs separate bundle variants' — which is comprehensive coverage of the domain.

5 / 5

Completeness

Explicitly answers both what ('How to add or modify Next.js experimental feature flags end-to-end') and when ('Use when editing config-shared.ts, config-schema.ts, ...') with concrete trigger phrases.

5 / 5

Trigger Term Quality

Includes the natural term 'feature flags' plus specific source-file names (config-shared.ts, next-server.ts, module.compiled.js) that serve as strong triggers for developers editing those files, but lacks synonyms like 'feature toggle' or 'flag'.

4 / 5

Distinctiveness Conflict Risk

Occupies a clear niche (Next.js experimental flag wiring) with highly specific file-name triggers, making conflict with unrelated skills minimal.

5 / 5

Total

19

/

20

Passed

Validation

87%

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

Validation — 14 / 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

Total

14

/

16

Passed

Repository

vercel/next.js

Path

.agents/skills/flags/SKILL.md

Reviewed

Table of Contents

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