Borrowing it
Nothing to install: this file belongs to JimmyPaolini/codebase. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/JimmyPaolini/codebase/main/.github/instructions/agents.instructions.mdgit clone --depth 1 https://github.com/JimmyPaolini/codebaseWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/instructions/jimmypaolini/codebase/agents)<a href="https://agentmods.dev/instructions/jimmypaolini/codebase/agents"><img src="https://agentmods.dev/badge/instructions/jimmypaolini/codebase/agents.svg" alt="Measured on agentmods" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.08292 | $0.08292 |
| Opus 5 | $0.04146 | $0.04146 |
| Sonnet 5 | $0.01658 | $0.01658 |
| Haiku 4.5 | $0.00829 | $0.00829 |
Grade B, and why
codebase agents.instructions.md scanned grade B with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 3d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Unrestricted tool accessmediumExcessive agency
A wildcard tool grant or "run any command" leaves no least-privilege boundary at all.
tools: ["*"] This is a copy
95% identical to intelligent-terminal agents.instructions.md — 231 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 1,069 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Custom Agent File Guidelines
Instructions for creating effective and maintainable custom agent files that provide specialized expertise for specific development tasks in GitHub Copilot.
Project Context
- Target audience: Developers creating custom agents for GitHub Copilot
- File format: Markdown with YAML frontmatter
- File naming convention: lowercase with hyphens (e.g.,
test-specialist.agent.md) - Location:
.github/agents/directory (repository-level) oragents/directory (organization/enterprise-level) - Purpose: Define specialized agents with tailored expertise, tools, and instructions for specific tasks
- Official documentation: https://docs.github.com/en/copilot/how-tos/use-copilot-agents/coding-agent/create-custom-agents
Required Frontmatter
Every agent file must include YAML frontmatter with the following fields:
---
description: "Brief description of the agent purpose and capabilities"
name: "Agent Display Name"
tools: ["read", "edit", "search"]
model: "Claude Sonnet 4.5"
target: "vscode"
infer: true
---
Core Frontmatter Properties
description (REQUIRED)
- Single-quoted string, clearly stating the agent's purpose and domain expertise
- Should be concise (50-150 characters) and actionable
- Example:
'Focuses on test coverage, quality, and testing best practices'
name (OPTIONAL)
- Display name for the agent in the UI
- If omitted, defaults to filename (without
.mdor.agent.md) - Use title case and be descriptive
- Example:
'Testing Specialist'
tools (OPTIONAL)
- List of tool names or aliases the agent can use
- Supports comma-separated string or YAML array format
- If omitted, agent has access to all available tools
- See "Tool Configuration" section below for details
model (STRONGLY RECOMMENDED)
- Specifies which AI model the agent should use
- Supported in VS Code, JetBrains IDEs, Eclipse, and Xcode
- Example:
'Claude Sonnet 4.5','gpt-4','gpt-4o' - Choose based on agent complexity and required capabilities
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 3d ago First seen · 1,069 lines · 8,292 tokens per session scan B b3d602399586
codebase agents.instructions.md is an instructions file published in the GitHub repository JimmyPaolini/codebase (0 stars, last pushed today), licensed MIT. It adds 8,292 tokens to every session, about $0.0415 per session on Opus 5. A static security scan graded it B with 1 finding (unrestricted tool access). It is 95% identical to intelligent-terminal agents.instructions.md, differing in 231 lines, and is treated as a copy.
Other instructions, from other repositories
codex AGENTS.md
AGENTS.md instructions for openai/codex, covering rust/codex-rs, the codex-core crate, code review rules, crate api surface and model visible context.
vscode buildNext.instructions.md
Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).
next.js AGENTS.md
AGENTS.md instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.
langchain AGENTS.md
AGENTS.md instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, applying the notice (cutover) and fallback chain (never fail the build).
spec-kit AGENTS.md
AGENTS.md instructions for github/spec-kit, covering agents.md, about spec kit and specify, quickstart — add a new integration in 5 steps, integration architecture and integrationmanifest — file tracking.