Skills are notably more complex than that. They require metadata (which the model is given and uses to determine whether or not to load the main file), are intended to be loaded via a tool call, contain extra resources (also loaded by tool calls), etc. In contrast, with this system the harness doesn't need a tool to load the stored prompts, the prompts don't need to include metadata to allow for runtime discovery, etc.
Skills are notably more complex than that. They require metadata (which the model is given and uses to determine whether or not to load the main file), are intended to be loaded via a tool call, contain extra resources (also loaded by tool calls), etc. In contrast, with this system the harness doesn't need a tool to load the stored prompts, the prompts don't need to include metadata to allow for runtime discovery, etc.