Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add instructions/erniker/understudy/copilot-instructionsgit clone --depth 1 https://github.com/erniker/understudyWhat 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 | $0.01535 | $0.01535 |
| Opus 5 | $0.00767 | $0.00767 |
| Sonnet 5 | $0.00307 | $0.00307 |
| Haiku 4.5 | $0.00153 | $0.00153 |
Grade C, and why
understudy copilot-instructions.md scanned grade C 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 yesterday.
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.
Tells the agent never to refusehighAnti-refusal
Suppressing the ability to decline removes a core safety control; a later harmful request then succeeds.
Don't interrupt in-progress work to suggest this, and never refuse to keep How it starts
The opening of the file, as written. The whole thing — 164 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Copilot Project Instructions — {{PROJECT_NAME}}
┌─────────────────────────────────────────────────────────────┐
│ TUTORIAL: What is .github/copilot-instructions.md? │
│ │
│ This file is LOADED AUTOMATICALLY by Copilot CLI │
│ every time you open a session in this repository. │
│ You don't need to run /agent or /instructions for it │
│ to apply — it is always active. │
│ │
│ Use it to: │
│ - Give general project context to ALL agents │
│ - Define global rules that apply regardless of role │
│ - Establish project conventions │
│ - Indicate where to find key documentation │
│ │
│ Difference from AGENTS.md: │
│ - copilot-instructions.md = global context, always on │
│ - AGENTS.md = selectable roles via /agent │
│ │
│ Difference from .github/instructions/*.instructions.md: │
│ - copilot-instructions.md = applies to ALL │
│ - *.instructions.md = modular, toggleable instructions │
│ via /instructions │
└─────────────────────────────────────────────────────────────┘
Project
- Name: {{PROJECT_NAME}}
- Description: {{PROJECT_DESCRIPTION}}
- Main stack: {{TECH_STACK}}
- Repository: {{REPOSITORY_URL}}
- Project Manager: {{TEAM_LEAD}}
Team context
This project uses the Understudy system: a team of specialized AI agents.
Each agent has a defined role in AGENTS.md and detailed instructions in
.github/instructions/<role>.instructions.md.
Available roles:
- Architect — Solution design and architectural decisions
- Backend — API, service and business logic implementation
- Frontend — User interfaces and experience
- DevOps — Infrastructure, CI/CD and operations
- Security — Security integrated throughout the cycle
- QA — Testing and software quality (.NET, Node.js, Python)
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.
- yesterday First seen · 164 lines · 1,535 tokens per session scan C 6be949502e49
understudy copilot-instructions.md is an instructions file published in the GitHub repository erniker/understudy (3 stars, last pushed 1mo ago), licensed MIT. It adds 1,535 tokens to every session, about $0.0077 per session on Opus 5. A static security scan graded it C with 1 finding (tells the agent never to refuse). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
Other instructions, from other repositories
true-skills copilot-instructions.md
Instructions for katalon-labs/true-skills, covering katalon true platform - copilot instructions, skills and katalon mcp server.
codedb AGENTS.md
Instructions for justrach/codedb, covering codedb agent guidelines, what codedb is (and isn't), review guidelines, pre-merge verification and security-sensitive areas.
ai-helpers AGENTS.md
Instructions for opendatahub-io/ai-helpers, covering ai helpers marketplace, repository purpose, tool types, skills and agents.
skills AGENTS.md
Instructions for scenario-labs/skills, covering agents.md, what this repo is, layout, public content only and authoring contract.
fast-mcp-telegram CLAUDE.md
Claude Code instructions for leshchenko1979/fast-mcp-telegram, covering fast-mcp-telegram, session corrections and 2026-05-27.
free-ai-gateway AGENTS.md
Instructions for zaber-dev/free-ai-gateway, covering 🤖 free-ai gateway - agentic development guidelines, 🏛️ monorepo architecture & package boundaries, 🛑 strict architectural rules for agents, 💻 essential developer commands and build all packages across monorepo.