hover · Opera DevTools MCP: Risk & Policy

WHAT IT DOES

What hover does on Opera DevTools MCP

AI agents invoke hover to trigger actions in Opera DevTools 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 hover needs a policy

Hovering over an element is a browser action that can trigger side effects such as tooltips, dropdown menus, JavaScript event handlers (mouseover, mouseenter), or dynamic content loading. It is not a pure read operation since it actively interacts with the browser. Severity is low because hover actions rarely cause irreversible or high-impact changes, but they can still trigger unintended UI interactions.

From the tool's definition 'Hover over the provided element' — triggers a browser interaction/action on a DOM element

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 Opera DevTools MCP, so you can run agents against it safely.

FAQ

Questions about hover

What does the hover tool do? +

Hover over the provided element. It is categorised as a Execute tool in the Opera DevTools 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 hover? +

Register the Opera DevTools 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 Opera DevTools MCP. 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 Opera DevTools MCP server (operasoftware/opera-devtools-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.