browser_mouse_move_xy · Playwright MCP: Risk & Policy

WHAT IT DOES

What browser_mouse_move_xy does on Playwright MCP

AI agents invoke browser_mouse_move_xy to trigger actions in 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.

WHY IT NEEDS A POLICY

Why browser_mouse_move_xy needs a policy

Moving the mouse is a browser automation action that interacts with the live browser environment. While it has no direct side effects on its own, it is part of an execution chain that can trigger hover effects, tooltips, dynamic UI changes, or precede clicks.

From the tool's definition 'Move mouse to a given position' — triggers a browser mouse movement action at specified coordinates

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

browser_mouse_move_xy Rate-limited

browser_mouse_move_xy 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_xy": {
      "limits": [
        {
          "counter": "browser_mouse_move_xy_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 Playwright MCP, so you can run agents against it safely.

FAQ

Questions about browser_mouse_move_xy

What does the browser_mouse_move_xy tool do? +

Move mouse to a given position. It is categorised as a Execute tool in the Playwright MCP 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_xy? +

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

What risk level is browser_mouse_move_xy? +

browser_mouse_move_xy 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_xy? +

Yes. Add a rate_limit block to the browser_mouse_move_xy 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_xy completely? +

Set action: deny in the PolicyLayer policy for browser_mouse_move_xy. 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_xy? +

browser_mouse_move_xy is provided by the Playwright MCP server (nzjami/mcpplaywright). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.