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/gabrielbryk/arc-devtools-mcp/agents-mdgit clone --depth 1 https://github.com/gabrielbryk/arc-devtools-mcpWrote 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/gabrielbryk/arc-devtools-mcp/agents-md)<a href="https://agentmods.dev/instructions/gabrielbryk/arc-devtools-mcp/agents-md"><img src="https://agentmods.dev/badge/instructions/gabrielbryk/arc-devtools-mcp/agents-md.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 | $0.00206 | $0.00206 |
| Opus 5 | $0.00103 | $0.00103 |
| Sonnet 5 | $0.00041 | $0.00041 |
| Haiku 4.5 | $0.00021 | $0.00021 |
Grade A, and why
arc-devtools-mcp AGENTS.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 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.
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.
This is a copy
92% identical to chrome-devtools-mcp AGENTS.md — 1 line 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.
What it actually says
This repository contains an MCP server and CLI for Chrome DevTools.
Instructions
- Use only scripts from
package.jsonto run commands. - Use
npm run buildto run tsc and test build. - Use
npm run testto build and run tests, run all tests to verify correctness. - Use
npm run test path-to-test.tsto build and run a single test file, for example,npm run test tests/McpContext.test.ts. - Use
npm run formatto fix formatting and get linting errors.
Rules for TypeScript
- Do not use
anytype. - Do not use
askeyword for type casting. - Do not use
!operator for type assertion. - Do not use
// @ts-ignorecomments. - Do not use
// @ts-nocheckcomments. - Do not use
// @ts-expect-errorcomments. - Prefer
for..ofinstead offorEach.
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 · 20 lines · 206 tokens per session scan A 78e249431c9c
arc-devtools-mcp AGENTS.md is an instructions file published in the GitHub repository gabrielbryk/arc-devtools-mcp (0 stars, last pushed 26d ago), licensed Apache-2.0. It adds 206 tokens to every session, about $0.0010 per session on Opus 5. A static security scan graded it A with 0 findings. It is 92% identical to chrome-devtools-mcp AGENTS.md, differing in 1 line, and is treated as a copy.
Other instructions, from other repositories
vscode ai-customization.instructions.md
Architecture documentation for VS Code AI Customization view. Use when working in src/vs/workbench/contrib/chat/browser/aiCustomization.
vscode agentHostTesting.instructions.md
Architecture documentation for VS Code AI Customization view. Use when working in src/vs/workbench/contrib/chat/browser/aiCustomization.
vscode-angular-snippets AGENTS.md
AGENTS.md instructions for johnpapa/vscode-angular-snippets, covering angular snippets for vs code — agent guide, repository structure, tech stack, build & run and test in browser (vscode.dev mode).
opencode-websearch AGENTS.md
Instructions for emilsvennesson/opencode-websearch, covering agents.md, commands, project structure, code style and functions.
second AGENTS.md
AGENTS.md instructions for Second-Inc/second, covering second, layout, general instructions (not necessarlly task dependent), about app ui changes and about local browser testing.
playwright-praman copilot-instructions.md
Copilot instructions for mrkanitkar/playwright-praman, covering praman v1.0 copilot instructions, project, architecture, agent skills (read before working) and code standards.