🔹 Feature: GitHub Copilot Custom Instructions & Agent Skills
🔹 What It Does: Enhances GitHub Copilot by embedding your team’s coding standards, architecture patterns, and reusable workflows so AI-driven suggestions, PR reviews, and agent tasks align to your organization instead of generic defaults.
Why It Matters
Out-of-the-box Copilot is smart, but it doesn’t know your naming conventions, security baselines, or that your IaC uses Bicep over Terraform. Custom Instructions make Copilot contextually aware of your standards, while Skills provide portable, reusable runbooks (scripts + templates + examples) it can invoke when needed. Together, they transform Copilot from a general assistant into a teammate who has read your onboarding docs.
What It’s Giving You
✅ Repository-Wide Instructions – .github/copilot-instructions.md defines always-on rules for architecture, coding style, build/test/deploy norms
✅ Path-Specific Instructions – .github/instructions/*.instructions.md applies different rules for IaC, pipelines, or language-specific folders
✅ Agent Skills – .github/skills/ with portable SKILL.md folders that bundle scripts and templates, invoked automatically or via /skill-name
✅ Cross-Surface Consistency – Skills work across VS Code, Copilot CLI, and cloud coding agents (open standard, also compatible with Claude)
✅ Progressive Context Loading – Skills inject their context only when triggered, keeping token usage efficient
✅ Priority Model Support – Personal > Repository > Organization instructions, allowing layered customization
✅ Smarter PR Reviews – Copilot reviews respect custom instructions out-of-the-box for consistent, policy-aligned feedback
💡 Pro Tip: Keep instructions files under ~1,000 lines with short, imperative bullets. Start with 10–20 rules and refine based on actual PR performance.
Real-Life Examples
🚀 https://github.com/MariuszFerdyn/microsoft-zero-trust-report
→ PowerShell CIS Benchmark automation for Azure & M365. Includes .github/copilot-instructions.md and AGENTS.md ensuring all contributors (human or AI) track Manual CIS items and follow permission rules.
🚀 https://github.com/MariuszFerdyn/LocalTemporaryTalkChat
→ Single-file encrypted PHP chat app with WebRTC and AES-GCM. Copilot instructions enforce strict rules: keys never leave the browser, no DB, no WebSockets, encrypted payloads only.
More Info
🌐 https://docs.github.com/en/copilot/how-tos/configure-custom-instructions/add-repository-instructions
🌐 https://docs.github.com/en/copilot/how-tos/use-copilot-agents/coding-agent/create-skills
🌐 https://code.visualstudio.com/docs/copilot/customization/agent-skills
🌐 https://github.com/github/awesome-copilot
