The /teach Skill
This article introduces the /teach skill, an AI agent skill designed for long-term, cumulative learning. Unlike one-off Q&A, /teach turns a directory into a persistent teaching workspace. It grounds lessons in vetted, high-trust resources (documentation, books) with citations, rather than relying on the model's parametric knowledge. It uses ADR-style learning records to track progress and dynamically adjusts lesson difficulty based on the zone of proximal development. The article details the workspace structure (lessons, reference, learning-records) and teaching philosophy: prioritizing storage strength over fluency illusion, and using desirable difficulty, retrieval practice, and spaced repetition for long-term retention. Ideal for engineers who want to learn a language, framework, or theory as a project over multiple sessions.