Borrowing it
Nothing to install: this file belongs to Robotti-io/copilot-security-instructions. 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/Robotti-io/copilot-security-instructions/main/.github/instructions/copilot-customization-files.instructions.mdgit clone --depth 1 https://github.com/Robotti-io/copilot-security-instructionsWrote 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/robotti-io/copilot-security-instructions/copilot-customization-files)<a href="https://agentmods.dev/instructions/robotti-io/copilot-security-instructions/copilot-customization-files"><img src="https://agentmods.dev/badge/instructions/robotti-io/copilot-security-instructions/copilot-customization-files/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/instructions/robotti-io/copilot-security-instructions/copilot-customization-files"><img src="https://agentmods.dev/badge/instructions/robotti-io/copilot-security-instructions/copilot-customization-files.svg" alt="Reviewed on agentmods" width="80" 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 | $0.00328 | $0.00328 |
| Opus 5.5 | $0.00131 | $0.00131 |
| Sonnet 5.5 | $0.00066 | $0.00066 |
| Haiku 4.5 | $0.00033 | $0.00033 |
Grade A, and why
copilot-security-instructions copilot-customization-files.instructions.md scanned grade A with 0 findings 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 1mo 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.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
What it actually says
Instructions for Copilot customization Markdown files
Required structure
- YAML frontmatter MUST be the first content in the file, delimited by
---lines. - The body MUST start after the frontmatter and a blank line.
- Use consistent, predictable headings:
# <Title>## Purpose## How to use## Rules## Examples(when relevant)
Frontmatter requirements by file type
.agent.md
- MUST have
description. - SHOULD have
name. - MAY have
tools,model,target,mcp-servers(when applicable).
.prompt.md
- SHOULD have
description. - SHOULD have
agentwhen the prompt is intended for agent mode. - Use
${input:...}placeholders for user-provided variables.
.instructions.md
- MUST have
applyTo. - MAY have
excludeAgentto limit to"code-review"or"coding-agent".
SKILL.md
- MUST have
name(lowercase-hyphenated) anddescription. - Keep the skill directory name lowercase and hyphenated.
Markdown formatting rules
- Prefer bullet lists for rules. Use “MUST/SHOULD/MAY”.
- Include at least one concrete example for non-trivial behaviors.
- Keep examples minimal but realistic.
- Use fenced code blocks with language tags.
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.
- 1mo ago First seen · 48 lines · 328 tokens per session scan A 8aa98f45ce3b
copilot-security-instructions copilot-customization-files.instructions.md is an instructions file published in the GitHub repository Robotti-io/copilot-security-instructions (42 stars, last pushed 5mo ago), licensed Apache-2.0. It adds 328 tokens to every session, about $0.0013 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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