Agent Skills: A Field Guide to the Third Pillar
Your agent can write code. But does it know how your team cuts a release? Can it run your incident playbook the same way twice, or does it improvise something a little different every time? That gap, between raw capability and a repeatable way of doing one specific job, is exactly what skills fill. A skill is procedural memory you write down once: a packaged, reusable how-to that the agent loads when it's relevant and runs the same way every time. This is the third leg of a trilogy with [Agent Memory](/guides/agent-memory-field-guide) and [The Agent's Self](/guides/agent-self-personality-identity), the three pillars from [Building Your Agentic OS](/guides/building-your-agentic-os). Identity is who the agent is, memory is what it knows, skills are how it does things. We start with what a skill really is, and what it isn't, then build one from a plain folder and a single file. We dig into the two halves of the craft that actually matter: writing a description that makes the agent reach for the skill at the right moment, and writing a body that makes it succeed once it does. We cover progressive disclosure (why the whole skill isn't sitting in context all the time), how to tell a skill apart from a memory or a tool, and how to version and share skills across a fleet without letting them rot. By the end you'll be able to take a capable, general-purpose agent and turn it into a specialist that does your specific jobs your specific way, on demand, every time. _This is a living document and will be updated as the tools and patterns evolve._
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