Domain 2 of GH-600 (18% of the exam) covers the tools, environments, and capabilities that GitHub Copilot agents can use. The centrepiece is the Model Context Protocol (MCP).
What Is MCP?
MCP is an open standard that allows AI models to connect to external tools in a structured, predictable way. Think of it as a universal adapter. Without MCP, every tool integration requires custom code. With MCP, a tool exposes a standard interface, and any MCP-compatible model can use it.
The GitHub MCP server is one of the most important implementations. It gives agents the ability to:
- Read and create issues
- Read and update pull requests
- Query repository contents
- Check workflow run statuses
- Manage labels and milestones
All without writing custom API code in every agent.
Configuring MCP in VS Code
MCP servers are configured in .vscode/mcp.json (workspace level) or VS Code user settings:
{
"servers": {
"github": {
"command": "npx",
"args": ["@modelcontextprotocol/server-github"],
"env": {
"GITHUB_PERSONAL_ACCESS_TOKEN": "${input:github-token}"
}
}
}
}
The ${input:github-token} pattern prompts for the token securely, rather than hardcoding it.
Scoped vs. Unscoped Tools
Domain 2 sub-skill 2.1 covers tool selection and permissions. The principle: agents should only have access to tools they need for the current task. This is analogous to least-privilege in security.
For a code review agent:
- ✅ Read repository contents
- ✅ Create PR review comments
- ❌ Create issues (not needed)
- ❌ Manage repo settings (not needed)
Tool scoping reduces the blast radius of an agent that misbehaves or is given ambiguous instructions.
Development Environment Integration (Sub-skill 2.3)
Sub-skill 2.3 covers how agents interact with the development environment. This includes:
AGENTS.md— a file the agent reads to understand the repository conventions, forbidden actions, and preferred patterns.github/copilot-instructions.md— instructions that Copilot reads to understand the project context- Git configuration — ensuring the agent uses a clearly identified committer identity
Domain 2 Quests
| Quest | Skill | Link |
|---|---|---|
| Q4 | Tool Selection & Permissions | Tool Selection & Permissions |
| Q5 | MCP Server Mastery | MCP Server Mastery |
| Q6 | Dev Environment Integration | Dev Environment Integration |
| Q7 | Safe Execution & Error Handling | Safe Execution & Error Handling |
These quests cover MCP configuration, token scoping, AGENTS.md authoring, and error escalation workflows.