vnc_mouse_scroll · VNC MCP Server MCP: Risk & Policy

WHAT IT DOES

What vnc_mouse_scroll does on VNC MCP Server

AI agents invoke vnc_mouse_scroll to trigger actions in VNC MCP 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 vnc_mouse_scroll needs a policy

Mouse scrolling is a browser/UI interaction that constitutes an external operation on a remote computer. It can trigger side effects (e.g., loading content, changing selections, activating UI elements) depending on the context. It falls under Execute as it performs a real-time input action on a remote system, consistent with the server's stated purpose of 'human-like input control' and computer control via VNC.

From the tool's definition 'Scroll the mouse' — triggers a physical input control action on a remote computer via VNC

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

vnc_mouse_scroll Rate-limited

vnc_mouse_scroll 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": {
    "vnc_mouse_scroll": {
      "limits": [
        {
          "counter": "vnc_mouse_scroll_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 VNC MCP Server, so you can run agents against it safely.

FAQ

Questions about vnc_mouse_scroll

What does the vnc_mouse_scroll tool do? +

Scroll the mouse. It is categorised as a Execute tool in the VNC MCP 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 vnc_mouse_scroll? +

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

What risk level is vnc_mouse_scroll? +

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

Can I rate-limit vnc_mouse_scroll? +

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

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

vnc_mouse_scroll is provided by the VNC MCP Server MCP server (volkan-m/vnc-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.