What changed is that the models got good enough to follow written instructions reliably. A skill is just a tested workflow in markdown that the agent reads and follows instead of improvising. You can also bundle scripts that the agent runs during the workflow, which covers what most people use lightweight MCP servers for, except the agent can read the script source and extend it.
Karpathy talks about an "economy of agents" and says we should stop writing HTML docs for humans and start writing markdown docs for agents [1]. Anthropic just shipped a skill-creator that benchmarks whether a skill still works after model updates. There are already tens of thousands of community skills on GitHub.
Distribution still feels early. Most useful skills are tiny. A markdown file, maybe one script. Useful enough to keep reusing, but not something anyone turns into a proper GitHub repo with a README and install instructions. So they stay on one machine.
I have been writing skills for my own agents for a while and I keep running into this. The format works. Moving them between machines or handing one to someone else does not.
Curious if others are hitting the same wall or if there are approaches I am missing.
[1] https://www.youtube.com/watch?v=kwSVtQ7dziU (Karpathy on No Briars podcast, skills discussion around 1:03:40)
