connect_serial · Network Device Assistant MCP: Risk & Policy

WHAT IT DOES

What connect_serial does on Network Device Assistant

AI agents invoke connect_serial to trigger actions in Network Device Assistant. 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 connect_serial needs a policy

Opening a serial console connection initiates an external session with a network device. This is an Execute-class action because it triggers an external operation (establishing a live console session) whose effects depend on the target device and port arguments. Misuse could grant unintended access to network infrastructure, making severity high.

From the tool's definition 'Open a serial console connection to a network device' — establishes an active connection to external hardware

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

connect_serial Rate-limited

connect_serial 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": {
    "connect_serial": {
      "limits": [
        {
          "counter": "connect_serial_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 Network Device Assistant, so you can run agents against it safely.

FAQ

Questions about connect_serial

What does the connect_serial tool do? +

Open a serial console connection to a network device. It is categorised as a Execute tool in the Network Device Assistant MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on connect_serial? +

Register the Network Device Assistant MCP server in PolicyLayer and add a rule for connect_serial: 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 Network Device Assistant. Nothing to install.

What risk level is connect_serial? +

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

Can I rate-limit connect_serial? +

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

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

connect_serial is provided by the Network Device Assistant MCP server (mgarabito/network-device-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.