start · McFlow MCP: Risk & Policy

WHAT IT DOES

What start does on McFlow

AI agents invoke start to trigger actions in McFlow. 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 start needs a policy

Starting a server is an Execute operation as it runs/triggers an external operation whose effects depend on context (which server, what load, what state). While the effects are somewhat reversible (stopping the server), the primary action is an execution trigger. This is not Destructive since starting a service is not irreversible data deletion, but it does carry high severity due to potential operational impact.

From the tool's definition 'Start n8n server' is a command that initiates an external service/process, which is an operation that triggers system state changes and potentially affects availability and resource allocation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

start Rate-limited

start 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": {
    "start": {
      "limits": [
        {
          "counter": "start_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 McFlow, so you can run agents against it safely.

FAQ

Questions about start

What does the start tool do? +

Start n8n server - replaces. It is categorised as a Execute tool in the McFlow MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on start? +

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

What risk level is start? +

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

Can I rate-limit start? +

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

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

start is provided by the McFlow MCP server (mckinleymedia/mcflow-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.