browser_mouse_move · Browser MCP Server MCP: Risk & Policy

WHAT IT DOES

What browser_mouse_move does on Browser MCP Server

AI agents invoke browser_mouse_move to trigger actions in Browser MCP Server. 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_move needs a policy

Mouse movement is a browser automation action that can trigger hover effects, tooltips, drag operations, or other UI interactions. While less impactful than a click, it still executes an external operation in the browser whose effects depend on the target coordinates and page state, placing it in the Execute category.

From the tool's definition Move the mouse to specific coordinates — triggers a browser action (mouse movement) that can interact with page elements and initiate UI operations depending on arguments.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

browser_mouse_move Rate-limited

browser_mouse_move 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_move": {
      "limits": [
        {
          "counter": "browser_mouse_move_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 MCP Server, so you can run agents against it safely.

FAQ

Questions about browser_mouse_move

What does the browser_mouse_move tool do? +

Move the mouse to specific coordinates (see browser_docs). It is categorised as a Execute tool in the Browser MCP Server 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_move? +

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

What risk level is browser_mouse_move? +

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

Can I rate-limit browser_mouse_move? +

Yes. Add a rate_limit block to the browser_mouse_move 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_move completely? +

Set action: deny in the PolicyLayer policy for browser_mouse_move. 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_move? +

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