| name | vscode-copilot-customization |
| description | > Use when this capability is needed. |
VS Code Copilot Customization
Decision Matrix
Use this matrix to recommend the right customization type. Always start here.
| Scenario | Best choice |
|---|
| Project-wide coding standards, always active | copilot-instructions.md |
| Rules only for specific file types / folders | *.instructions.md with applyTo |
| Works with multiple AI agents (Claude, Copilot, etc.) | AGENTS.md |
| Reusable task you invoke manually in chat | Prompt file (.prompt.md) |
| Specialized workflow with tool restrictions or model choice | Custom agent (.agent.md) |
| Portable capability reusable across projects + CLI + cloud agents | Agent skill (SKILL.md) |
| Auto-run commands at agent lifecycle points (format, lint, enforce) | Hook (.json) |
| Bundle multiple customizations to share or distribute | Agent plugin (plugin.json) |
Quick decision flow
Do you want it ON automatically for every request?
├─ YES → Instructions (.instructions.md / copilot-instructions.md / AGENTS.md)
└─ NO, I invoke it manually →
Does it need persistent persona, tool restrictions, or model choice?
├─ YES → Custom Agent (.agent.md)
└─ NO →
Is it a reusable multi-agent portable capability?
├─ YES → Agent Skill (SKILL.md)
└─ NO → Prompt File (.prompt.md)
Do you want to run shell commands around agent actions?
└─ YES → Hook (hooks/*.json)
Do you want to bundle everything for distribution?
└─ YES → Agent Plugin (plugin.json)
1. Custom Instructions
Always-on context and rules. Stored in .github/copilot-instructions.md (workspace-wide), AGENTS.md (multi-agent), or *.instructions.md (file-scoped via applyTo glob).
Read references/instructions.md when asked to create, write, or configure custom instructions.
2. Prompt Files
Reusable task templates invoked manually via / slash command. Stored in .github/prompts/*.prompt.md.
Read references/prompt-files.md when asked to create a prompt file or reusable chat task.
3. Custom Agents
Specialized Copilot persona with tool whitelist, model choice, and optional handoffs. Stored in .github/agents/*.agent.md.
Read references/custom-agents.md when asked to create a custom agent or chat mode.
4. Agent Skills
Portable, progressive-loading capabilities that work across VS Code, Copilot CLI, and cloud agents. Stored in .github/skills/<name>/SKILL.md.
Read references/agent-skills.md when asked to create a skill or when the user asks about SKILL.md format, frontmatter fields, or skill best practices.
5. Hooks
Shell commands triggered at agent lifecycle events (PostToolUse, Stop, etc.). Stored in .github/hooks/*.json.
Read references/hooks.md when asked to create a hook, set up auto-formatting, or run commands around agent actions.
6. Agent Plugins
Bundle skills, agents, hooks, and MCP servers for distribution. Defined in plugin.json.
Read references/plugins.md when asked to create, publish, or install an agent plugin.
File Locations Reference
| Type | Workspace location | User profile location |
|---|
| Always-on instructions (Copilot) | .github/copilot-instructions.md | — |
| Always-on instructions (multi-agent) | AGENTS.md | — |
| Targeted instructions | .github/instructions/*.instructions.md | ~/.vscode/instructions/ |
| Prompt files | .github/prompts/*.prompt.md | ~/.vscode/prompts/ |
| Custom agents | .github/agents/*.agent.md | ~/.vscode/agents/ |
| Agent skills | .github/skills/<name>/SKILL.md | ~/.vscode/skills/ |
| Hooks | .github/hooks/*.json | ~/.vscode/hooks/ |
| Claude Code agents | .claude/agents/*.md | — |
| Claude Code rules | .claude/rules/*.md | — |
AI Generation Commands
/init → workspace-wide copilot-instructions.md
/create-instruction → targeted .instructions.md
/create-prompt → .prompt.md file
/create-agent → .agent.md file
/create-skill → agent skill directory
/create-hook → hook JSON file
Open the Chat Customizations editor for a visual overview:
Command Palette → "Chat: Open Chat Customizations"
Reference files
references/instructions.md – Custom instructions templates and settings
references/prompt-files.md – Prompt file templates and input variables
references/custom-agents.md – Agent templates and handoff configuration
references/agent-skills.md – Skill format, progressive loading, official docs
references/hooks.md – Hook templates, events, naming convention
references/plugins.md – Plugin structure and distribution
references/frontmatter-reference.md – Complete frontmatter field reference for all types
references/examples.md – Real-world examples organized by use case
Source: danielsitek/skills — distributed by TomeVault.