Taking Skills apart

I went through the GitHub of the very popular make-photo-stamp-archive. Engineering-wise it isn’t complicated — at its core is one SKILL.md and an image prompt template. What’s impressive is that the author really knows what looks good, and broke that taste down into concrete rules.

Taking apart one simple and one complex Skill, I found that a Skill’s complexity isn’t a measure of skill level but of how many different kinds of information and operations the task needs; the simplest needs only one SKILL.md.

Putting OpenAI’s, Claude’s and Gemini’s agent concepts side by side, I found that what has really converged is Skills and MCP: a Skill covers “how it should be done,” MCP covers “what can be called while doing it.”

Marketplaces for Skills are already forming (OpenAI Plugins, the Claude Code Marketplace, the Gemini Extension Gallery), but they’ll look more and more like a market, not necessarily like an App Store.