spawn_worker · Claude Operator MCP: Risk & Policy

WHAT IT DOES

What spawn_worker does on Claude Operator

AI agents invoke spawn_worker to trigger actions in Claude Operator. 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 spawn_worker needs a policy

Based on the server description which explicitly mentions 'spawns worker sessions', this tool likely creates and launches new autonomous worker processes or sessions. Spawning workers constitutes execution of new processes/agents. The empty description lowers confidence, but the server context strongly implies this triggers external operations.

From the tool's definition Tool name 'spawn_worker' on a server described as spawning worker sessions; description is empty and uninformative.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

spawn_worker Rate-limited

spawn_worker 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": {
    "spawn_worker": {
      "limits": [
        {
          "counter": "spawn_worker_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 Claude Operator, so you can run agents against it safely.

FAQ

Questions about spawn_worker

What does the spawn_worker tool do? +

spawn_worker. It is categorised as a Execute tool in the Claude Operator MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on spawn_worker? +

Register the Claude Operator MCP server in PolicyLayer and add a rule for spawn_worker: 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 Claude Operator. Nothing to install.

What risk level is spawn_worker? +

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

Can I rate-limit spawn_worker? +

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

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

spawn_worker is provided by the Claude Operator MCP server (moygulati/claude-operator). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.