browser_mouse_wheel · Browser MCP: Risk & Policy

WHAT IT DOES

What browser_mouse_wheel does on Browser

AI agents invoke browser_mouse_wheel to trigger actions in Browser. 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.

WHY IT NEEDS A POLICY

Why browser_mouse_wheel needs a policy

Scrolling the mouse wheel is a browser interaction that can trigger JavaScript events, lazy loading, infinite scroll, or other dynamic page behaviors. It goes beyond passive reading and constitutes an executed browser action.

From the tool's definition 'Scroll the mouse wheel' — triggers a browser interaction/action via Playwright automation

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

browser_mouse_wheel Rate-limited

browser_mouse_wheel 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.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "browser_mouse_wheel": {
      "limits": [
        {
          "counter": "browser_mouse_wheel_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Browser, so you can run agents against it safely.

FAQ

Questions about browser_mouse_wheel

What does the browser_mouse_wheel tool do? +

Scroll the mouse wheel (see browser_docs). It is categorised as a Execute tool in the Browser MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on browser_mouse_wheel? +

Register the Browser MCP server in PolicyLayer and add a rule for browser_mouse_wheel: 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 Browser. Nothing to install.

What risk level is browser_mouse_wheel? +

browser_mouse_wheel is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit browser_mouse_wheel? +

Yes. Add a rate_limit block to the browser_mouse_wheel 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.

How do I block browser_mouse_wheel completely? +

Set action: deny in the PolicyLayer policy for browser_mouse_wheel. 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.

What MCP server provides browser_mouse_wheel? +

browser_mouse_wheel is provided by the Browser MCP server (ricardodeazambuja/browser-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.