selectDevice · Lyngdorf MCP Server MCP: Risk & Policy

WHAT IT DOES

What selectDevice does on Lyngdorf MCP Server

AI agents use selectDevice to create or update resources in Lyngdorf MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Lyngdorf MCP Server environment.

WHY IT NEEDS A POLICY

Why selectDevice needs a policy

This tool changes the active device connection state, which is a reversible write/configuration action. It doesn't read data, execute code, or perform destructive/financial operations. Misuse could redirect audio control to an unintended device, but the effect is reversible.

From the tool's definition Select and connect to a specific device by number

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

selectDevice Rate-limited

selectDevice stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "selectDevice": {
      "limits": [
        {
          "counter": "selectdevice_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Lyngdorf MCP Server, so you can run agents against it safely.

FAQ

Questions about selectDevice

What does the selectDevice tool do? +

Select and connect to a specific device by number. It is categorised as a Write tool in the Lyngdorf MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on selectDevice? +

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

What risk level is selectDevice? +

selectDevice is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit selectDevice? +

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

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

selectDevice is provided by the Lyngdorf MCP Server MCP server (thejens/lyngdorf-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.