hover · MCP Selenium Server MCP: Risk & Policy

WHAT IT DOES

What hover does on MCP Selenium Server

AI agents invoke hover to trigger actions in MCP Selenium 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 hover needs a policy

Hovering over an element is a browser automation action that can trigger UI side effects (e.g., revealing dropdowns, tooltips, dynamic content). It is not purely a read operation since it causes external state changes in the browser environment. Severity is low because hover actions alone rarely cause significant harm, but they can trigger unintended UI interactions.

From the tool's definition 'moves the mouse to hover over an element' — triggers a browser interaction/action

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

hover Rate-limited

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.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "hover": {
      "limits": [
        {
          "counter": "hover_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 MCP Selenium Server, so you can run agents against it safely.

FAQ

Questions about hover

What does the hover tool do? +

moves the mouse to hover over an element. It is categorised as a Execute tool in the MCP Selenium 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 hover? +

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

What risk level is hover? +

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

Can I rate-limit hover? +

Yes. Add a rate_limit block to the 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 hover completely? +

Set action: deny in the PolicyLayer policy for 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 hover? +

hover is provided by the MCP Selenium Server MCP server (sapangupta63/mcp-selenium-extended). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.