Testing vs Design · both proven

skill-creator vs ui-styling

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.

skill-creator

Create new skills, modify and improve existing skills, and measure skill performance. Use when users want to create a skill from scratch, edit, or optimize an existing skill, run evals to test a skill, benchmark skill performance with variance analysis, or optimize a skill's description for better triggering accuracy.

Category: Testing
Source: anthropics/skills
License: Not stated
Proof model: claude-opus-5-5
Brief: “Write a complete SKILL.md for a skill called release-notes that turns a list of merged pull request titles into customer-facing release notes grouped by feature, fix and breaking change, in the tone of a small developer-tools company. Present the finished SKILL.md as a single HTML page, with the frontmatter and body shown in a code block and a short note under it on how you decided what to include.”
Skill commit: dbd4588

Without the skillWith skill-creator

⇆

Without, runWith skill-creator, run3 independent runs per side, none selected by hand.

Download the with-skill page

ui-styling

Create beautiful, accessible user interfaces with shadcn/ui components (built on Radix UI + Tailwind), Tailwind CSS utility-first styling, and canvas-based visual designs. Use when building user interfaces, implementing design systems, creating responsive layouts, adding accessible components (dialogs, dropdowns, forms, tables), customizing themes and colors, implementing dark mode, generating…

Category: Design
Source: nextlevelbuilder/ui-ux-pro-max-skill
License: MIT
Proof model: claude-opus-5-5
Brief: “Build the main screen of Quayside, an internal tool a small logistics company uses to track container shipments: a sidebar, a filter bar, a table of 12 shipments with status, ETA and port, a detail panel for the selected shipment with a timeline, and an empty state for when filters match nothing. Make it accessible and keyboard friendly.”
Skill commit: d14efff

Without the skillWith ui-styling

⇆

Without, runWith ui-styling, 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 skill-creator or alternatives to ui-styling.