フロントエンド作業のためのリファレンスとなる Model Context Protocol サーバーです。一度インストールすれば、Claude Desktop、Cursor、VS Code、Zed、Continue などのあらゆるコーディングエージェントが、あなたのUIに対してリアルな目と手を持つことができます：
axe_audit — 生のHTML（jsdom経由）またはライブURL（Playwright経由）に対して、実際の axe-core ルールエンジンを実行します。WCAGのインパクト別にグループ化された違反と修正リンクを返します。
page_screenshot — あらゆるURLやCSSセレクターのヘッドレスChromiumによるPNG画像を取得します。ビューポート / DPR / カラースキーム / waitForSelector の制御が可能です。
bundle_budget_check — dist/ ディレクトリを走査し、gzip（+オプションでbrotli）サイズを計算し、グローバルまたはエントリーごとのKB予算を強制します。CI対応のパス/フェイルJSONを返します。
design_token_diff — 2つの W3C DTCG / Style Dictionary トークンファイルの構造的な差分をとります。追加 / 削除 / 変更されたトークンを $type を考慮した注釈付きで報告します。
storybook_story_run — iframe.html?id=… 経由でヘッドレスChromiumに単一のStorybookストーリーを読み込み、スクリーンショットを撮り、レンダリングされたコンポーネントに対してのみaxe監査を実行します。
scaffold_react_component — 型定義されたReactコンポーネント（関数型 / forwardRef / ポリモーフィック as）に加え、オプションでVitestテストとStorybookストーリーを出力します。
すべてのツールは、モデルが推論可能な構造化JSONを返します。エディターごとの専用ラッパーは不要です。
npm i -g @ashios15/mcp-frontend-tools
# Optional — enables page_screenshot, storybook_story_run, and URL-mode axe_audit
npm i -g playwright
npx playwright install chromiumNode 20以上 が必要です。Playwrightがなくてもサーバーは起動しますが、それら3つのツールを呼び出すと「playwrightをインストールしてください」という明確なエラーが返されます。
~/Library/Application Support/Claude/claude_desktop_config.json （またはWindowsの同等パス）に追加します：
{
"mcpServers": {
"frontend-tools": {
"command": "mcp-frontend-tools"
}
}
}Settings → MCP → Add new server:
{
"frontend-tools": { "command": "mcp-frontend-tools" }
}.vscode/mcp.json に追加します：
{
"servers": {
"frontend-tools": { "command": "mcp-frontend-tools" }
}
}npx @modelcontextprotocol/inspector mcp-frontend-toolsRelated MCP server: UX/UI Tools for React + Material-UI
axe_audit{
url?: string; // require playwright
html?: string; // jsdom
tags?: string[]; // default: wcag2a/aa + wcag21aa + wcag22aa + best-practice
selector?: string; // URL mode only
timeoutMs?: number; // default 15000
}違反および不完全なルールを impact、help、helpUrl、およびルールごとに最大5つの失敗ノード例とともに返します。
page_screenshot{
url: string;
outPath: string; // absolute; parent dirs auto-created
selector?: string;
fullPage?: boolean;
width?: number; // default 1280
height?: number; // default 800
deviceScaleFactor?: number;// default 2
colorScheme?: "light" | "dark" | "no-preference";
waitForSelector?: string;
timeoutMs?: number;
}bundle_budget_check{
buildDir: string;
budgetKb?: number; // default 250 (gzipped)
perEntryBudgetKb?: Record<string, number>;// key = path substring, longest match wins
ext?: string[]; // default [".js",".mjs",".cjs",".css"]
includeBrotli?: boolean;
}すべてのファイルについて、生 / gzip / brotli サイズ、適用された予算、および status: "pass" | "fail" を返します。
design_token_diff{
beforePath: string;
afterPath: string;
ignoreKeys?: string[];
}W3C DTCG形式 ($value, $type) を理解します。$ で始まるグループメタデータキーは無視されます。色や寸法の変更には note が注釈として付けられます。
storybook_story_run{
storybookUrl: string; // e.g. http://localhost:6006
storyId: string; // e.g. components-button--primary
screenshotPath?: string;
runAxe?: boolean; // default true
viewport?: { width: number; height: number };
colorScheme?: "light" | "dark" | "no-preference";
timeoutMs?: number;
}${storybookUrl}/iframe.html?viewMode=story&id=${storyId} を読み込み、#storybook-root を待機し、ページエラーとストーリーにスコープされたaxe違反を報告します。
scaffold_react_component{
name: string; // PascalCase
outDir: string; // absolute
variant?: "functional" | "forwardRef" | "polymorphic";
withTests?: boolean; // default true
withStory?: boolean; // default true
props?: Array<{ name: string; type: string; required?: boolean; defaultValue?: string }>;
}エージェントは型付きの契約を得る。 すべてのツールは、モデルがイントロスペクト可能なZodで検証されたJSONスキーマです。
ローカルでのハルシネーションがない。 Axeの違反は正規表現ではなく、実際のaxe-coreエンジンから得られます。バンドルサイズは推定値ではなく、実際の zlib 圧縮から得られます。
構成可能。 bundle_budget_check で失敗 → エージェントに最大ファイルを page_screenshot に渡すよう依頼 → 画像を視覚的リグレッションステップに送る。すべてMCPを通じて行えます。
安定したインターフェース。 ツールはバージョンアップの裏側で変更されますが、あなたの .vscode/mcp.json は変更されません。
git clone https://github.com/ashios15/mcp-frontend-tools.git
cd mcp-frontend-tools
npm install
npm run test # 3 unit tests (bundle + tokens + scaffold)
npm run build
npm run inspector # opens MCP Inspector against the built server
node scripts/smoke.mjs # quick stdio tools/list checkMIT © ashios15
フロントエンド作業のためのリファレンスとなる Model Context Protocol サーバーです。一度インストールすれば、Claude Desktop、Cursor、VS Code、Zed、Continue などのあらゆるコーディングエージェントが、あなたのUIに対してリアルな目と手を持つことができます：
axe_audit — 生のHTML（jsdom経由）またはライブURL（Playwright経由）に対して、実際の axe-core ルールエンジンを実行します。WCAGのインパクト別にグループ化された違反と修正リンクを返します。
page_screenshot — あらゆるURLやCSSセレクターのヘッドレスChromiumによるPNG画像を取得します。ビューポート / DPR / カラースキーム / waitForSelector の制御が可能です。
bundle_budget_check — dist/ ディレクトリを走査し、gzip（+オプションでbrotli）サイズを計算し、グローバルまたはエントリーごとのKB予算を強制します。CI対応のパス/フェイルJSONを返します。
design_token_diff — 2つの W3C DTCG / Style Dictionary トークンファイルの構造的な差分をとります。追加 / 削除 / 変更されたトークンを $type を考慮した注釈付きで報告します。
storybook_story_run — iframe.html?id=… 経由でヘッドレスChromiumに単一のStorybookストーリーを読み込み、スクリーンショットを撮り、レンダリングされたコンポーネントに対してのみaxe監査を実行します。
scaffold_react_component — 型定義されたReactコンポーネント（関数型 / forwardRef / ポリモーフィック as）に加え、オプションでVitestテストとStorybookストーリーを出力します。
すべてのツールは、モデルが推論可能な構造化JSONを返します。エディターごとの専用ラッパーは不要です。
npm i -g @ashishjoshi/mcp-frontend-tools
# Optional — enables page_screenshot, storybook_story_run, and URL-mode axe_audit
npm i -g playwright
npx playwright install chromiumNode 20以上 が必要です。Playwrightがなくてもサーバーは起動しますが、それら3つのツールを呼び出すと「playwrightをインストールしてください」という明確なエラーが返されます。
~/Library/Application Support/Claude/claude_desktop_config.json （またはWindowsの同等パス）に追加します：
{
"mcpServers": {
"frontend-tools": {
"command": "mcp-frontend-tools"
}
}
}Settings → MCP → Add new server:
{
"frontend-tools": { "command": "mcp-frontend-tools" }
}.vscode/mcp.json に追加します：
{
"servers": {
"frontend-tools": { "command": "mcp-frontend-tools" }
}
}npx @modelcontextprotocol/inspector mcp-frontend-toolsaxe_audit{
url?: string; // require playwright
html?: string; // jsdom
tags?: string[]; // default: wcag2a/aa + wcag21aa + wcag22aa + best-practice
selector?: string; // URL mode only
timeoutMs?: number; // default 15000
}違反および不完全なルールを impact、help、helpUrl、およびルールごとに最大5つの失敗ノード例とともに返します。
page_screenshot{
url: string;
outPath: string; // absolute; parent dirs auto-created
selector?: string;
fullPage?: boolean;
width?: number; // default 1280
height?: number; // default 800
deviceScaleFactor?: number;// default 2
colorScheme?: "light" | "dark" | "no-preference";
waitForSelector?: string;
timeoutMs?: number;
}bundle_budget_check{
buildDir: string;
budgetKb?: number; // default 250 (gzipped)
perEntryBudgetKb?: Record<string, number>;// key = path substring, longest match wins
ext?: string[]; // default [".js",".mjs",".cjs",".css"]
includeBrotli?: boolean;
}すべてのファイルについて、生 / gzip / brotli サイズ、適用された予算、および status: "pass" | "fail" を返します。
design_token_diff{
beforePath: string;
afterPath: string;
ignoreKeys?: string[];
}W3C DTCG形式 ($value, $type) を理解します。$ で始まるグループメタデータキーは無視されます。色や寸法の変更には note が注釈として付けられます。
storybook_story_run{
storybookUrl: string; // e.g. http://localhost:6006
storyId: string; // e.g. components-button--primary
screenshotPath?: string;
runAxe?: boolean; // default true
viewport?: { width: number; height: number };
colorScheme?: "light" | "dark" | "no-preference";
timeoutMs?: number;
}${storybookUrl}/iframe.html?viewMode=story&id=${storyId} を読み込み、#storybook-root を待機し、ページエラーとストーリーにスコープされたaxe違反を報告します。
scaffold_react_component{
name: string; // PascalCase
outDir: string; // absolute
variant?: "functional" | "forwardRef" | "polymorphic";
withTests?: boolean; // default true
withStory?: boolean; // default true
props?: Array<{ name: string; type: string; required?: boolean; defaultValue?: string }>;
}エージェントは型付きの契約を得る。 すべてのツールは、モデルがイントロスペクト可能なZodで検証されたJSON-Schemaです。
ローカルでのハルシネーションがない。 Axeの違反は正規表現ではなく、実際のaxe-coreエンジンから得られます。バンドルサイズは推定値ではなく、実際の zlib 圧縮から得られます。
構成可能。 bundle_budget_check で失敗 → エージェントに最大ファイルを page_screenshot に渡すよう依頼 → 画像を視覚的リグレッションステップに送る。すべてMCPを通じて行えます。
安定したインターフェース。 ツールはバージョンアップの裏側で変更されますが、あなたの .vscode/mcp.json は変更されません。
npm install
npm run test # 3 unit tests (bundle + tokens + scaffold)
npm run build
npm run inspector # opens MCP Inspector against the built server
node scripts/smoke.mjs # quick stdio tools/list checkMIT © Ashish Joshi
AIアシスタント（Claude、Copilot、Cursor）にフロントエンド開発ツール（コンポーネントの雛形作成、バンドル分析、アクセシビリティチェック、レスポンシブデザインガイド）へのアクセスを提供する Model Context Protocol (MCP) サーバーです。
ツール | 説明 |
| テスト、ストーリー、CSSモジュールを含む型付きReactコンポーネントを生成 |
| ビルドディレクトリをスキャンして巨大なJS/CSSを特定し、結果を報告 |
| HTMLに対する静的なWCAG 2.2チェックと修正案の提示 |
| レスポンシブCSS、コンテナクエリ、Tailwindパターンの生成 |
~/Library/Application Support/Claude/claude_desktop_config.json に追加します：
{
"mcpServers": {
"frontend-tools": {
"command": "node",
"args": ["/path/to/mcp-frontend-tools/dist/index.js"]
}
}
}.vscode/settings.json に追加します：
{
"github.copilot.chat.mcpServers": {
"frontend-tools": {
"command": "node",
"args": ["${workspaceFolder}/mcp-frontend-tools/dist/index.js"]
}
}
}"アバター、名前、バイオのプロップを持つUserProfileCardコンポーネントの雛形を作成して"
AIが scaffold_react_component を呼び出し、以下が返されます：
UserProfileCard.tsx — forwardRefを使用した型付きコンポーネント
UserProfileCard.test.tsx — Testing Libraryによるテスト
UserProfileCard.stories.tsx — Storybookストーリー
UserProfileCard.module.css — CSSモジュール
index.ts — バレルエクスポート
"dist/フォルダのバンドルサイズの問題を分析して"
AIが analyze_bundle を呼び出し、巨大なファイル、推奨事項、要約テーブルを含むマークダウンレポートを返します。
src/
├── index.ts # MCP server setup (stdio transport)
└── tools/
├── index.ts # Tool definitions + router
├── scaffold-component.ts # React component generator
├── bundle-analyzer.ts # Build output analyzer
├── a11y-checker.ts # Static WCAG checks
└── responsive-guide.ts # Responsive CSS pattern generatornpm install
npm run build
npm run inspector # Test with MCP InspectorMIT
Run the axe-core accessibility ruleset against an HTML string (jsdom) or a live URL (Playwright). Returns violations grouped by impact with fix guidance and helpUrl links.
| Name | Required | Description | Default |
|---|---|---|---|
| url | No | Fully qualified URL to audit. Requires playwright installed. | |
| html | No | Raw HTML string to audit (jsdom, no JS execution). | |
| tags | No | axe rule tags to include. Defaults to ['wcag2a','wcag2aa','wcag21a','wcag21aa','wcag22aa','best-practice']. | |
| selector | No | CSS selector to scope the audit (URL mode only). | |
| timeoutMs | No | Default 15000. |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations provided, so description carries full burden. It discloses the audit scope (axe-core), return format (grouped violations with guidance/links), and that URL mode uses Playwright. No contradictions.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
Two sentences, no fluff. First sentence states core action and modes, second describes output format. Information density is high.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
No output schema, but description sufficiently hints at return structure (violations grouped by impact, fix guidance, helpUrl). Parameters well described, tool behavior clear. Complete for the complexity level.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema has 100% description coverage. Description adds context beyond schema: clarifies dual mode (url/html), defaults for tags, selector only for URL, timeout default. Adds value.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
Description clearly states the tool runs axe-core accessibility rules on HTML or URL, returns violations grouped by impact with fix guidance and helpUrl links. This is specific and distinguishes it from sibling tools like screenshot or bundler checks.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
Description explains two usage modes (HTML string vs live URL) and mentions prerequisite (playwright for URL). Does not explicitly state when not to use or alternatives, but context with siblings makes it clear.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Walk a build directory, measure raw + gzip (+ optional brotli) sizes per file, and flag files that exceed a global or per-entry KB budget. CI-friendly JSON output.
| Name | Required | Description | Default |
|---|---|---|---|
| buildDir | Yes | Absolute path to the build output directory (e.g. dist, .next/static). | |
| budgetKb | No | Global size budget in KB. Flags any file above this (gzipped). Default: 250. | |
| perEntryBudgetKb | No | Per-file budgets in KB keyed by glob-ish substring match. Matching file is checked against the most specific (longest) matching key. | |
| ext | No | File extensions to include (default: ['.js','.mjs','.cjs','.css']). | |
| includeBrotli | No | Also compute brotli sizes (slower). |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden. It explicitly states it walks a directory, measures sizes, and flags exceedances. It also mentions CI-friendly JSON output. While it doesn't disclose potential actions (e.g., read-only or any side effects), the described behavior aligns with a read-only check, making it fairly transparent.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
Two sentences, each purposeful. Front-loaded with the core action ('Walk a build directory...'). No wasted words. The structure is optimal for quick agent comprehension.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
No output schema is present, so the description should clarify the output format. It mentions 'CI-friendly JSON output' but does not specify structure, exit codes, or how budgets are compared. With 5 parameters and a nested object, more detail would help the agent use it effectively. Score 3 reflects adequate but not complete guidance.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100%, so baseline is 3. The description adds minimal value beyond the schema: it mentions 'global or per-entry KB budget' but does not explain the glob matching or default values. The schema already describes each parameter adequately. Thus, the description does not significantly enhance parameter understanding.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description uses a specific verb ('Walk') and resource ('build directory') and clearly states the action: measure raw/gzip/brotli sizes and flag budget violations. This distinguishes it from sibling tools like 'axe_audit' (accessibility) and 'scaffold_react_component', which serve entirely different purposes.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description clearly implies the tool is for bundle size checks, providing context for use. It does not explicitly state when not to use it or compare with alternatives, but siblings are in unrelated domains, so the context is sufficient. A score of 4 reflects clear context without formal exclusions.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Diff two design-token JSON files (W3C DTCG / Style Dictionary style). Reports added, removed, and changed tokens with $type-aware classification. Useful for PR review of design-system changes.
| Name | Required | Description | Default |
|---|---|---|---|
| beforePath | Yes | Path to the baseline tokens JSON (Style Dictionary / W3C DTCG format). | |
| afterPath | Yes | Path to the new tokens JSON. | |
| ignoreKeys | No | Dot-path keys to ignore (e.g. ['$description','$extensions']). |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden of behavioral disclosure. It states the tool reports added, removed, and changed tokens with $type-aware classification, which implies a read-only comparison. It does not mention side effects or required permissions, but for a diff tool, the behavior is sufficiently transparent.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is only two sentences long, front-loading the core action in the first sentence and adding a use case in the second. Every word is informative with no fluff.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the tool has no output schema, the description adequately describes what the diff reports (added, removed, changed tokens). It mentions the input format and the classification approach. The absence of output format details is a minor gap, but overall the description is sufficient for an agent to understand the tool's behavior.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100% with clear descriptions for all three parameters. The tool description adds high-level context (e.g., format, output behavior) but does not provide additional meaning about the parameters beyond the schema. Baseline of 3 is appropriate.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the tool diffs design-token JSON files, specifies the format (W3C DTCG / Style Dictionary), and lists what it reports (added, removed, changed tokens with type-aware classification). The use case (PR review) distinguishes it from sibling tools (e.g., axe_audit, bundle_budget_check).
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description explicitly mentions a use case ('Useful for PR review of design-system changes'), which guides when to use it. It does not specify when not to use it or name alternatives, but the context is clear and no sibling tool overlaps with this diffing functionality.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Launch headless Chromium, navigate to a URL, and save a PNG screenshot. Supports element selectors, full-page capture, dark mode, and custom viewports. Requires the optional playwright peer dependency.
| Name | Required | Description | Default |
|---|---|---|---|
| url | Yes | URL to screenshot. | |
| outPath | Yes | Absolute file path to write PNG to. Parent dirs will be created. | |
| selector | No | CSS selector to screenshot instead of the viewport. | |
| fullPage | No | Capture the full scrollable page (default: false). | |
| width | No | Viewport width (default 1280). | |
| height | No | Viewport height (default 800). | |
| deviceScaleFactor | No | DPR (default 2). | |
| colorScheme | No | ||
| waitForSelector | No | Wait for this selector before capturing. | |
| timeoutMs | No |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description must carry behavioral disclosure. It discloses headless Chromium usage, supports for selectors, full-page, dark mode, and viewports. It also mentions the optional Playwright dependency. Missing details on error handling and default behaviors, but still provides significant transparency.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
Two sentences, both substantive. First sentence defines core action; second lists key features and a dependency. No redundant or extraneous words.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the tool's complexity (10 parameters, no output schema), the description provides a good high-level overview. It specifies the browser engine, supported features, and a dependency. It could mention return behavior (writes file to disk) or default values, but the schema covers defaults. Overall complete given the context.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 80%, so baseline is 3. The description provides a high-level grouping of features (e.g., 'Supports element selectors, full-page capture, dark mode, and custom viewports') but does not add detail beyond the schema. For the two parameters without schema descriptions (timeoutMs, waitForSelector? waitForSelector has description, timeoutMs does not), the description does not compensate.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
Description clearly states 'Launch headless Chromium, navigate to a URL, and save a PNG screenshot.' It uses specific verbs and a concrete resource. Distinct from siblings like axe_audit or bundle_budget_check, which address different tasks.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description implies when to use (when a screenshot of a web page is needed) but does not explicitly exclude alternatives or provide when-not-to-use guidance. Siblings are clearly different, so context is clear.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Write a TypeScript React component, optional test, and optional Storybook story into outDir. Supports functional, forwardRef, and polymorphic (as prop) variants.
| Name | Required | Description | Default |
|---|---|---|---|
| name | Yes | ||
| outDir | Yes | Absolute directory to write the component files into. Created if missing. | |
| variant | No | ||
| withTests | No | ||
| withStory | No | ||
| props | No |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations provided, so description must disclose behavioral traits. It mentions file creation and that outDir is created if missing, but does not state whether files are overwritten, side effects, or required permissions. This is insufficient for a write operation.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is a single sentence, concise and front-loaded, but could benefit from a second sentence to improve clarity without significant length increase.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
With 6 parameters, no output schema, and no annotations, the description is incomplete. It does not explain return value, error conditions, or full behavior of the props parameter.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is low (17%), and the description does not explain parameters like variant, props, withTests, withStory. It mentions variants but does not elaborate on differences between functional, forwardRef, polymorphic.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states it writes a TypeScript React component with optional test and Storybook story, and supports three variants. This distinguishes it from sibling tools which are unrelated (auditing, budget, screenshots).
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description provides basic context but lacks explicit when-to-use or when-not-to-use guidance. Since siblings are in different domains, the need for alternatives is less, but no prerequisites or exclusions are mentioned.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Load a single Storybook story in headless Chromium via iframe.html, optionally screenshot it, and run an axe-core audit against the rendered output. Requires playwright.
| Name | Required | Description | Default |
|---|---|---|---|
| storybookUrl | Yes | Base URL of a running Storybook, e.g. http://localhost:6006. | |
| storyId | Yes | Story id as it appears in the URL (e.g. 'components-button--primary'). | |
| screenshotPath | No | If set, save a PNG of the rendered story to this absolute path. | |
| runAxe | No | Run an axe-core audit of the rendered story (default true). | |
| viewport | No | ||
| colorScheme | No | ||
| timeoutMs | No |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description must cover behavioral traits. It discloses the main actions (load, screenshot, audit) and the need for Playwright, but lacks details on side effects like browser resource usage, error handling, or that it returns axe results.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
Two sentences with no fluff. The purpose and key requirement are front-loaded in the first sentence, making it efficient.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
The tool has 7 parameters, nested objects, and no output schema. The description omits return values, parameter interactions, and behavioral details like error scenarios or required environment setup, making it incomplete for a complex tool.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 57%, so the description should add meaning, but it does not explain parameters beyond the schema. It only gives a generic summary, leaving parameter nuances (e.g., viewport, colorScheme, timeoutMs) solely to the schema.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states it loads a single Storybook story via headless Chromium, with optional screenshot and axe-core audit. It distinguishes from siblings like page_screenshot (general) and axe_audit (general audit) by focusing on Storybook stories.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description implies usage for testing Storybook stories but does not explicitly contrast with sibling tools or specify when not to use it. It only mentions a prerequisite (Playwright), not exclusion criteria.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Recent tool additions, removals, and schema changes observed during successful MCP inspections.
v2.0.0axe_auditbundle_budget_checkdesign_token_diffpage_screenshotscaffold_react_componentstorybook_story_runScored across 6 tools
Each tool targets a distinct frontend concern: accessibility auditing, bundle sizing, design token diffs, page screenshots, component scaffolding, and Storybook testing. No two tools could be confused.
All tool names follow a consistent 'object_action' or 'domain_action' pattern with lowercase underscores (e.g., axe_audit, design_token_diff). No mixing of conventions.
Six tools is an appropriate size for a frontend utility toolkit. Each tool provides a distinct, useful function without being overwhelming or too sparse.
The set covers key frontend tasks: accessibility, performance, design tokens, component generation, and testing. A minor gap is the lack of a linting or formatting tool, but the surface is coherent for its scope.
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