vnc_type_string · VNC MCP Server MCP: Risk & Policy

WHAT IT DOES

What vnc_type_string does on VNC MCP Server

AI agents invoke vnc_type_string 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_type_string needs a policy

Typing a string into a remote computer via VNC constitutes executing an input action on an external system. This can trigger arbitrary operations depending on what application is focused (e.g., typing commands into a terminal, entering data into forms, or interacting with any UI element).

From the tool's definition 'Type a string' on a VNC-controlled computer; server description states 'human-like input control' and 'control computers via VNC'

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

vnc_type_string Rate-limited

vnc_type_string 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_type_string": {
      "limits": [
        {
          "counter": "vnc_type_string_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_type_string

What does the vnc_type_string tool do? +

Type a string. 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_type_string? +

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

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

Can I rate-limit vnc_type_string? +

Yes. Add a rate_limit block to the vnc_type_string 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_type_string completely? +

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

vnc_type_string 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.