High Risk →

browser_hover

browser_hover

How to control browser_hover ↓

What browser_hover does on Playwright

AI agents invoke browser_hover to trigger actions in Playwright. 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.

High Risk

Why browser_hover needs a policy

Playwright is a browser automation framework. 'browser_hover' almost certainly moves the mouse pointer over an element, which can trigger UI events (dropdowns, tooltips, state changes). This is an external browser action whose effects depend on arguments, placing it in Execute. Description is empty, reducing confidence slightly.

From the tool's definition Tool name 'browser_hover' on a Playwright server alongside tools like browser_click, browser_drag — implies triggering a browser hover/mouse action over a UI element.

Documented attack patterns abuse exactly the kind of access browser_hover gives an agent:

How to control browser_hover

PolicyLayer is an MCP gateway — it sits between your AI agents and Playwright, and nothing reaches the server without passing your rules. This is the rule we recommend for browser_hover:

policy.json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "browser_hover": {
      "limits": [
        {
          "counter": "browser_hover_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

browser_hover 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.

  1. Create a free account and register Playwright — nothing to install.
  2. Add this policy — paste it, or build it visually.
  3. Point your MCP client (Claude, Cursor, anything) at your gateway URL.
RATE-LIMIT THIS TOOL →

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Related tools and policies

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Questions about browser_hover

What does the browser_hover tool do? +

browser_hover. It is categorised as a Execute tool in the Playwright 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_hover? +

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

What risk level is browser_hover? +

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

Can I rate-limit browser_hover? +

Yes. Add a rate_limit block to the browser_hover 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_hover completely? +

Set action: deny in the PolicyLayer policy for browser_hover. 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_hover? +

browser_hover is provided by the Playwright MCP server (@playwright/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Playwright tool call.

Start from Playwright, 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.

68 Playwright tools catalogued and risk-classified — across an index of 43,000+ MCP servers.

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