Design vs Testing · both proven

banner-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.

banner-design

Design banners for social media, ads, website heroes, creative assets, and print. Multiple art direction options with optional generated or supplied visuals. Actions: design, create, generate banner. Platforms: Facebook, Twitter/X, LinkedIn, YouTube, Instagram, Google Display, website hero, print. Styles: minimalist, gradient, bold typography, photo-based, illustrated, geometric, retro…

Category: Design
Source: nextlevelbuilder/ui-ux-pro-max-skill
License: MIT
Proof model: claude-opus-5-5
Brief: “Design a set of launch banners for Brightline Coffee's new cold brew cans, as one HTML page showing each banner at its real size: a 1200x628 social ad, a 1080x1080 square post, a 728x90 leaderboard, and a 1600x500 website hero. Price $3.50 a can, in stores June 1.”
Skill commit: bf41cbc

Without the skillWith banner-design

⇆

Without, runWith banner-design, run3 independent runs per side, none selected by hand.

Download the with-skill page

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

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 banner-design or alternatives to skill-creator.