Skills are not only Markdown files. I often structure my skills as small Python scripts and the actual Markdown is only the skill front matter and maybe some brief documentation. You can even stick an OpenAPI schema or whatever you see fit.

If you often need timezone conversion, sounds like a `timezones` skill exposing a few lines in a Python script. Boom. No MCP needed. No server needed. It's just files, all the way down. If you find yourself operating with dates a lot maybe you need a `datetime` skill wrapping a bunch of tiny scripts. Fully deterministic, cheap on tokens, and you can even run them without an agent (shocking nowadays :P)

As I identify repetitive actions I add (Claude adds) new scripts to the Skill to save tokens in the future, whereas MCP I'm at the mercy of the server provider. E.g. I have a Magic the Gathering skill with a bunch of tools to retrieve card databases, simulate hands, get card images...

This article enlightened me: https://mariozechner.at/posts/2025-11-02-what-if-you-dont-ne...

This is why I don't feel Skills are orthogonal. They feel like MCP on steroids since the scripts can be composed with Bash et al (huge battle-tested ecosystem, plenty in the training set)... and you don't need crappy abstractions like "resources" (yes, that's a thing in MCP) when the agent has a shell and a filesystem.

I've used this pattern to great success. Nowadays I just share these `.skill` packages with my friends (I think they're just a fancy ZIP file?)

The only thing missing for me is credentials and sandboxing (see my GP post). I have my own ideas on how to solve this (and some of that Claude in cloud already solves for me), but it's not easy (which is how MCP won).