3 articles
A skill bundles two attack surfaces in one folder: a body that becomes trusted context the moment it triggers, and scripts that run with real privileges. Add supply-chain risk and you have a dependency, not a document.
A tool is one capability, MCP is connectivity to external systems, a Skill is packaged know-how for using what you already have, and a subagent is an isolated context window. How to pick the right layer instead of the wrong one out of habit.
An Agent Skill packages one piece of procedural expertise into a folder the model loads on demand. Progressive disclosure is what makes it cheap: install a hundred skills and pay for the one that fires.