sdk_hover · UI Bridge MCP: Risk & Policy

WHAT IT DOES

What sdk_hover does on UI Bridge MCP

AI agents invoke sdk_hover to trigger actions in UI Bridge 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 sdk_hover needs a policy

This tool triggers a UI interaction (hover action) on an external application via the SDK, which constitutes executing a browser/UI action. While hovering itself has limited direct side effects, it can trigger UI state changes, tooltips, dropdowns, or other dynamic behaviors in the target app, making it an Execute-category tool with medium severity.

From the tool's definition Hover over an element in the SDK app

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

sdk_hover Rate-limited

sdk_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": {
    "sdk_hover": {
      "limits": [
        {
          "counter": "sdk_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 UI Bridge MCP, so you can run agents against it safely.

FAQ

Questions about sdk_hover

What does the sdk_hover tool do? +

Hover over an element in the SDK app. It is categorised as a Execute tool in the UI Bridge 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 sdk_hover? +

Register the UI Bridge MCP server in PolicyLayer and add a rule for sdk_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 UI Bridge MCP. Nothing to install.

What risk level is sdk_hover? +

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

Can I rate-limit sdk_hover? +

Yes. Add a rate_limit block to the sdk_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 sdk_hover completely? +

Set action: deny in the PolicyLayer policy for sdk_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 sdk_hover? +

sdk_hover is provided by the UI Bridge MCP server (qontinui/ui-bridge-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.