Design vs Testing · both proven

canvas-design vs skill-creator

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.

canvas-design

Create beautiful visual art in .png and .pdf documents using design philosophy. You should use this skill when the user asks to create a poster, piece of art, design, or other static piece. Create original visual designs, never copying existing artists' work to avoid copyright violations.

Category: Design
Source: anthropics/skills · 182,147 stars
License: Not stated
Proof model: claude-opus-5-5
Brief: “Build the one-page site for Blue Hour, a monthly jazz night at a small club: a poster-style hero with a drawn inline SVG illustration, the lineup with short bios, the schedule, a photo-strip section drawn with SVG, ticket tiers, and a footer with the address. Make it feel like a printed poster brought to the web, with motion.”
Skill commit: dbd4588

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 · 182,147 stars
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

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 canvas-design or alternatives to skill-creator.