Testing vs Design · both proven

skill-creator vs web-artifacts-builder

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

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

Download the with-skill page

web-artifacts-builder

Suite of tools for creating elaborate, multi-component claude.ai HTML artifacts using modern frontend web technologies (React, Tailwind CSS, shadcn/ui). Use for complex artifacts requiring state management, routing, or shadcn/ui components - not for simple single-file HTML/JSX artifacts.

Category: Design
Source: anthropics/skills
License: Not stated
Proof model: claude-opus-5-5
Brief: “Build a single-page trip planner for a four-day weekend in Lisbon as one self-contained HTML file: a day-by-day itinerary with editable stops, a running budget that totals by category, a packing checklist with progress, and a simple map panel drawn with inline SVG that highlights the selected day's stops. State should live in the page and update everywhere when anything changes.”
Skill commit: dbd4588

Without the skillWith web-artifacts-builder

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Without, runWith web-artifacts-builder, 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 web-artifacts-builder.