hover · Chromium ARM64 Browser MCP: Risk & Policy

WHAT IT DOES

What hover does on Chromium ARM64 Browser

AI agents invoke hover to trigger actions in Chromium ARM64 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 hover needs a policy

Hovering is an interactive browser action that triggers event listeners (onmouseover, onmouseenter, etc.) and can execute arbitrary JavaScript. While not destructive or financial, it goes beyond passive read operations—it actively manipulates browser state and can trigger side effects.

From the tool's definition Tool performs browser automation action 'hover over an element on the page' which triggers DOM events and may execute JavaScript event handlers. Server description confirms 'browser automation' capability with 'JavaScript execution' support.

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 Chromium ARM64 Browser, so you can run agents against it safely.

FAQ

Questions about hover

What does the hover tool do? +

Hover over an element on the page. It is categorised as a Execute tool in the Chromium ARM64 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 hover? +

Register the Chromium ARM64 Browser 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 Chromium ARM64 Browser. 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 Chromium ARM64 Browser MCP server (nfodor/mcp-chromium-arm64). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.