In the Claude agent ecosystem, two concepts look similar on the surface but serve fundamentally different roles. Only one of them gets talked about. Skills get all the attention — and fairly so. They're easy to grasp: write a markdown file, define a workflow, and you're done. The agent detects it as a reusable pattern. It's like teaching the agent how to do something . Clear input, clear output, shareable across teams. Hooks are a different story. "Skills tell the agent what it can do. Hooks tell the agent what it must — and must not — do." The problem: nobody is talking about hooks Hooks like PreToolUse , PostToolUse , Notification , and Stop live at the edges of execution. They don't add new capabilities. Instead, they govern agent behavior — and that distinction is everything.…