Install the browser specified in the config. Call this if you get an error about the browser not being installed.
AI agents invoke browser_install to trigger actions in Better Playwright MCP. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.
Installing a browser involves executing system-level operations to download and install software onto the host machine. This goes beyond a simple write and constitutes execution of an installation process with side effects on the host environment. Misuse could lead to installing unwanted or malicious browser versions, but blast radius is moderate since it's constrained to browser installation.
From the tool's definition 'Install the browser specified in the config' — installs software on the host system
Documented attack patterns abuse exactly the kind of access browser_install gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Better Playwright MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for browser_install:
{
"version": "1",
"default": "deny",
"tools": {
"browser_install": {
"limits": [
{
"counter": "browser_install_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}browser_install stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.
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Install the browser specified in the config. Call this if you get an error about the browser not being installed. It is categorised as a Execute tool in the Better Playwright MCP MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Better Playwright MCP server in PolicyLayer and add a rule for browser_install: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Better Playwright MCP. Nothing to install.
browser_install is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the browser_install rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for browser_install. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
browser_install is provided by the Better Playwright MCP server (livoras/better-playwright-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Better Playwright MCP, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
29 Better Playwright MCP tools catalogued and risk-classified — across an index of 43,000+ MCP servers.