select_port · Electron MCP: Risk & Policy

WHAT IT DOES

What select_port does on Electron

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

WHY IT NEEDS A POLICY

Why select_port needs a policy

An AI agent can call select_port faster than any human can review — one bad instruction and it creates or modifies resources in Electron by the hundred, each call as confident as the last.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

select_port Rate-limited

select_port 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": {
    "select_port": {
      "limits": [
        {
          "counter": "select_port_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 Electron, so you can run agents against it safely.

FAQ

Questions about select_port

What does the select_port tool do? +

Select which Electron app port when multiple are connected. Pass 0 to clear. It is categorised as a Write tool in the Electron MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on select_port? +

Register the Electron MCP server in PolicyLayer and add a rule for select_port: 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 Electron. Nothing to install.

What risk level is select_port? +

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

Can I rate-limit select_port? +

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

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

select_port is provided by the Electron MCP server (ohah/electron-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.