vnc_connect · VNC MCP Server MCP: Risk & Policy

WHAT IT DOES

What vnc_connect does on VNC MCP Server

AI agents invoke vnc_connect 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_connect needs a policy

Establishing a VNC connection is the gateway action that enables full computer control (mouse, keyboard, screen capture, command execution). While 'connect' itself is a setup action, it triggers an external session with significant blast radius: once connected, an AI agent can execute arbitrary actions on the remote system.

From the tool's definition Connect to a VNC server — initiates an active remote desktop connection, enabling subsequent control of a remote computer

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

vnc_connect Rate-limited

vnc_connect 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_connect": {
      "limits": [
        {
          "counter": "vnc_connect_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_connect

What does the vnc_connect tool do? +

Connect to a VNC server. 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_connect? +

Register the VNC MCP Server MCP server in PolicyLayer and add a rule for vnc_connect: 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_connect? +

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

Can I rate-limit vnc_connect? +

Yes. Add a rate_limit block to the vnc_connect 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_connect completely? +

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

vnc_connect 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.