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/drisplabs/browser-mcp/agents-mdgit clone --depth 1 https://github.com/drisplabs/browser-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/drisplabs/browser-mcp/agents-md)<a href="https://agentmods.dev/instructions/drisplabs/browser-mcp/agents-md"><img src="https://agentmods.dev/badge/instructions/drisplabs/browser-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 | $0.03211 | $0.03211 |
| Opus 5 | $0.01605 | $0.01605 |
| Sonnet 5 | $0.00642 | $0.00642 |
| Haiku 4.5 | $0.00321 | $0.00321 |
Grade A, and why
browser-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 4d 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.
How it starts
The opening of the file, as written. The whole thing — 196 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Snapshot & Interaction Pipeline — Audit Results
Comprehensive audit across 7 parallel review agents examining the full extraction and interaction pipeline for bugs where the agent's perception diverges from reality.
Critical (agent can't complete tasks)
C1. Iframe element coordinates are iframe-relative, not viewport-relative
Agent 1, Finding 3 | layout-extractor.ts:413-458
Batch path uses getBoundingClientRect() inside iframes, returning iframe-local coordinates. Input.dispatchMouseEvent expects viewport-relative. Clicks on iframe elements (cookie banners, embedded forms) hit wrong positions.
C2. Cross-origin iframe elements can't be resolved from main CDP session
Agent 3, Finding 2 | element-resolver.ts, session-manager.ts:499
CDP session is created once per page. backendNodeId for cross-origin iframe elements can't be resolved via DOM.resolveNode/DOM.getBoxModel from the main frame session. Cookie consent banners (OneTrust, Cookiebot) are common cross-origin iframes.
C3. EID collision suffix shifts silently when DOM order changes
Agent 5, Finding 2+7 | element-identity.ts:132-143, element-registry.ts:67-80
Collision resolution assigns -2, -3 by iteration order. If elements reorder between snapshots, suffixes shift and the agent silently acts on the wrong element. Common with sorted lists, infinite scroll, and any dynamic reordering.
C4. Stale element retry picks first label+kind match with no disambiguation
Agent 5, Finding 6 | stale-element-retry.ts:64-65
nodes.find(n => n.label === node.label && n.kind === node.kind) returns the first match. For pages with repeated elements ("Add to cart" x10), the wrong element is targeted silently.
Major (agent works around it poorly)
M1. opacity:0, clip-path, transform:scale(0) not detected as invisible
Agent 1, Finding 1 | layout-extractor.ts:123-140
computeVisibility() only checks display:none, visibility:hidden, and zero bbox. Invisible elements (loading spinners with opacity:0, off-screen transforms) reported as visible. Agent tries to interact with them.
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.
- 4d ago First seen · 196 lines · 3,211 tokens per session scan A 67a001b69f70
browser-mcp AGENTS.md is an instructions file published in the GitHub repository drisplabs/browser-mcp (15 stars, last pushed 18d ago), licensed MIT. It adds 3,211 tokens to every session, about $0.0161 per session on Opus 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.
Other instructions, from other repositories
rustwright AGENTS.md
AGENTS.md instructions for Skyvern-AI/rustwright, covering repository instructions, public boundary, pull-request review, local verification and browser launches.
cloakbrowser-mcp AGENTS.md
Instructions for swimmwatch/cloakbrowser-mcp, covering agents.md, about the project, golden rules, project layout and daily commands.
mcp-stealth-chrome AGENTS.md
Instructions for RobithYusuf/mcp-stealth-chrome, covering mcp-stealth-chrome — agent guide, product and repository map, hard constraints, working defaults and architecture invariants.
eyebrowse CLAUDE.md
Claude Code instructions for Evil-Bane/eyebrowse, covering claude.md — eyebrowse build notes, layout, run, pinned versions (lockstep matters) and key constraints (encoded in code — don't "simplify" away).
webnav-core CLAUDE.md
Claude Code instructions for lucyfuur94/webnav-core, covering claude.md — webnav-core / webnav, subagent model (settled), cli categories (settled), walk vs use — do not conflate (settled) and what this project is.
patchright-browser AGENTS.md
AGENTS.md instructions for rickicode/patchright-browser, covering agents.md — instructions for ai agents, what is this?, how to install, how to add mcp server and in your mcp config.