I have yet to see an "agent skill" that does not match this description.

How I use skills:

- Create a skill to perform some common task

- Watch the agent use it

- Wait until the agent makes a mistake

- Ask it to update the skill to warn it against making that mistake again

I think that, using that iterative process, I end up with something better than just asking it to perform the task plainly

One observation: ask an LLM to write a skill, it tends to make them overly verbose and prescriptive. Often, something briefer and human-written actually works better

Another: I generally let the LLM propose edits to the skill, but I review them carefully and often modify them, because I find it has a tendency to solve the current problem at the price of worsening the solution to a previous one

Oh, skills are absolutely useful for giving the LLM distilled knowledge of things that it doesn't just know ("off the top of its head" so to speak). For example, a company's coding style guide is something that could be very useful to express as a skill.

They are useful for packaging all the related bits together. Some instructions on the line to add to the main prompt, detailed policy doc that spells out details, troubleshooting docs, the code itself, etc.