Design vs Testing · both proven

prototype vs writing-guidelines

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.

prototype

Build a throwaway prototype to answer a design question. Use when the user wants to sanity-check whether a state model or logic feels right, or explore what a UI should look like.

Category: Design
Source: mattpocock/skills
License: MIT
Proof model: claude-opus-5-5
Brief: “We are designing the order state model for a food delivery app. An order can be placed, accepted by the restaurant, being prepared, ready for pickup, picked up by a courier, and delivered. The customer can cancel until the restaurant starts preparing; the restaurant can cancel at any time before pickup; a cancellation after payment triggers a refund, partial if food was already prepared. We are not sure this logic is right. Build a throwaway prototype as a single HTML page that lets someone on the team drive an order through these states and see where the rules break or get confusing.”
Skill commit: 5beb35b

Without the skillWith prototype

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Without, runWith prototype, run3 independent runs per side, none selected by hand.

Download the with-skill page

writing-guidelines

Review docs/prose for Writing Guidelines compliance. Use when asked to "review my docs", "check writing style", "audit prose", "review docs voice and tone", or "check this page against the writing handbook".

Category: Testing
Source: vercel-labs/agent-skills
License: Not stated
Proof model: claude-opus-5-5
Brief: “Review and rewrite this getting-started page for Pipewell, a data pipeline CLI. The draft opens with two paragraphs of company history, mixes 'you' and 'the user', buries the install command in the fourth paragraph, uses passive voice throughout, and ends without a next step. Write the improved page as a single HTML document, followed by a short list of what you changed and why.”
Skill commit: 063bee9

Without the skillWith writing-guidelines

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Without, runWith writing-guidelines, 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 prototype or alternatives to writing-guidelines.