Testing vs Frontend · both proven

grilling 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.

grilling

Grill the user relentlessly about a plan, decision, or idea. Use when the user wants to stress-test their thinking, or uses any 'grill' trigger phrases.

Category: Testing
Source: mattpocock/skills
License: MIT
Proof model: claude-opus-5-5
Brief: “Here is my plan. I want to launch a paid newsletter for independent game developers in six weeks. It will cost $8 a month, come out every Tuesday, and cover marketing tips, funding opportunities and interviews with developers who shipped on Steam. I have 1,200 followers on X and no email list yet. My goal is 500 paying subscribers in the first year. Grill me on this plan, and present the result as a single HTML page: every question you would ask me, in the order you would ask it, why each one matters, and what a weak answer would tell you.”
Skill commit: 5beb35b

Without the skillWith grilling

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Without, runWith grilling, 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 grilling or alternatives to vercel-react-native-skills.