GitHub shows how to teach Copilot your repo with instructions, skills, and MCP

GitHub published on 12 October 2026 a Copilot app beginners guide on giving Copilot lasting project context instead of re-explaining house rules every task. Four layers: repository custom instructions in `.github/copilot-instructions.md`, path-specific files under `.github/instructions` with an applyTo field, agent skills as folders under `.github/skills` with a SKILL.md for repeatable procedures such as quality checks, and custom agents under `.github/agents` for broader roles such as accessibility review. MCP servers connect Copilot to outside tools; the post walks through Playwright so Copilot can open the app in a browser and click through flows after a change. The advice is to start small: put one convention you keep repeating into copilot-instructions.md, then add skills and agents only for workflows you already repeat. Awesome Copilot is pointed to for community-ready examples to adapt.