GitHub Copilot Customizer

Tailor GitHub Copilot through six customization methods. This skill provides navigation to detailed guides.

When to Use This Skill

Use this when you need to:

• •Create or modify .github/copilot-instructions.md
• •Build custom agents (.agent.md), prompts (.prompt.md), or instruction files (.instructions.md)
• •Configure MCP servers for external tool access
• •Choose the right customization method for your needs
• •Set up the .github/ folder structure

Quick Decision Guide

Need to...
├─ Apply rule to ALL code? → copilot-instructions.md
├─ Apply rule to specific file types? → .instructions.md  
├─ Create reusable workflow? → .agent.md
├─ Template a common task? → .prompt.md
├─ Package domain knowledge? → SKILL.md
└─ Add external tools? → mcp.json (+ MCP server)

Six Customization Methods

Critical: Use exact file extensions or detection fails.

Prerequisites

• •VS Code with GitHub Copilot extension
• •Enable instruction files in settings:
  json

  {
    "github.copilot.chat.codeGeneration.useInstructionFiles": true,
    "chat.agent.enabled": true
  }
  

Directory Structure

.github/
├── copilot-instructions.md
├── agents/
│   ├── planner.agent.md
│   └── reviewer.agent.md
├── prompts/
│   └── generate-component.prompt.md
├── instructions/
│   ├── python-coding.instructions.md
│   └── typescript-coding.instructions.md
└── skills/
    └── <skill-name>/SKILL.md

.vscode/
└── mcp.json  # VS Code only

Quick Start

1. •Create workspace baseline: Copy template to .github/copilot-instructions.md
2. •Add custom agent: Use template → save as .github/agents/<name>.agent.md
3. •Create prompt: Use template → save as .github/prompts/<name>.prompt.md
4. •Add instruction file: Use template → save as .github/instructions/<name>.instructions.md
5. •Configure MCP: See MCP Setup Guide

Details and Examples

Complete Guides

• •Detailed Guides - In-depth information on all methods
  • •Agent frontmatter properties (9 properties with handoffs)
  • •Available models and tools
  • •Prompt file properties
  • •Glob patterns for instruction files
  • •Skills vs Instructions comparison
  • •Combining methods patterns
• •Agent Examples - Common patterns (Planner, Implementer, Reviewer)
• •Instruction Examples - Language/framework specific
• •Chat Tools Reference - Complete list of 47+ tools and tool sets
• •VS Code Settings - Essential Copilot settings organized by category
• •MCP Setup - Complete MCP server configuration guide with stdio/HTTP types

Templates

• •Agent Template - Generic .agent.md starter
• •Prompt Template - Generic .prompt.md starter
• •Instructions Template - Generic .instructions.md starter
• •Copilot Instructions Template - Workspace baseline starter

Troubleshooting

External Resources

• •Custom Agents Documentation
• •Agent Skills Documentation
• •Custom Instructions
• •Prompt Files
• •Chat Tools Reference
• •MCP Servers
• •Agent Skills Standard