Real Plugins Need Motors: Skills Should Teach Tools, Not Pretend to Be Them

Watch the short video companion Read or comment on the complete paper: English edition | French edition I spent a long time building AI workflows before admitting something painfully simple: a folder full of instructions is not automatically a tool. A SKILL.md can be brilliant. An AGENTS.md can save a repository. A plugin manifest can package a clean idea. None of them, by themselves, can validate a file, inspect live state, call a service, reject malformed input, or prove that an action happened. That distinction matters because agent ecosystems are expanding faster than their vocabulary. We use skill , plugin , tool , hook , resource , and MCP server as if they were interchangeable. They are not. My rule after this research is direct: A skill should teach the agent how to use a capability. A real plugin should make that capability available. When the task requires action, the plugin needs a motor. The moment my own plugin exposed the problem This article became a case study inside my own workshop. I inspected a memory plugin that was not fake. It already had executable tools, a server surface, tests, and useful routes. Yet its activation instructions pushed Codex toward selecting and dispatching a large agent job before establishing whether memory was needed at all. Nothing was syntactically broken. The architecture was simply asking activation to do too much. Activating a plugin should make capabilities available. It should not behave like a dispatch order. That difference sounds small until the workspace grows. One skill becomes ten. Every correction becomes a permanent rule. Every successful workflow becomes another Markdown file. Soon the model spends the beginning of each task reading the workshop labels instead of touching the work. I call this context debt . The debt appears as hesitation, instruction conflicts, stale rules, broad triggers, and repeated searching. The model is not necessarily weaker. We may have consumed its useful attention before it reach