Design vs Frontend · both proven

mcp-builder vs vercel-react-native-skills

Both skills were run through Claude twice: once on a fixed brief without the skill, once with it. The briefs differ because each is written for the job the skill claims to do, so compare each skill against its own baseline, then decide which difference matters for your work. They are in different categories, so this is a choice of job, not a head-to-head on the same job.

mcp-builder

Guide for creating high-quality MCP (Model Context Protocol) servers that enable LLMs to interact with external services through well-designed tools. Use when building MCP servers to integrate external APIs or services, whether in Python (FastMCP) or Node/TypeScript (MCP SDK).

Category: Design
Source: anthropics/skills
License: Not stated
Proof model: claude-opus-5-5
Brief: “Build an MCP server in TypeScript that gives an agent read access to a team's Linear-style issue tracker through a REST API: tools to search issues, get one issue with comments, and list a project's open issues by priority. Present it as a single HTML page with the full source of each file, the tool schemas, how errors and pagination are handled, and how to run and connect it.”
Skill commit: dbd4588

Without the skillWith mcp-builder

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Without, runWith mcp-builder, run3 independent runs per side, none selected by hand.

Download the with-skill page

vercel-react-native-skills

React Native and Expo best practices for building performant mobile apps. Use when building React Native components, optimizing list performance, implementing animations, or working with native modules. Triggers on tasks involving React Native, Expo, mobile performance, or native platform APIs.

Category: Frontend
Source: vercel-labs/agent-skills
License: Not stated
Proof model: claude-opus-5-5
Brief: “Review and improve this React Native screen, and present the findings and the improved code as a single HTML page. ```jsx export default function Feed() { const [posts, setPosts] = useState([]); useEffect(() => { fetch(API + '/posts').then(r => r.json()).then(setPosts); }); return ( <ScrollView> {posts.map(p => ( <View> <Image source={{ uri: p.image }} style={{ width: '100%', height: 300 }} /> <Text onPress={() => navigation.navigate('Post', { post: p })}>{p.title}</Text> </View> ))} </ScrollView> ); } ```”
Skill commit: 1a2c79d

Without the skillWith vercel-react-native-skills

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Without, runWith vercel-react-native-skills, run3 independent runs per side, none selected by hand.

Download the with-skill page

We don’t pick a winner for you: the pages are the evidence. Both proofs can be repeated with the brief, model and commit shown above. See alternatives to mcp-builder or alternatives to vercel-react-native-skills.