create_agent · RetellAI MCP Server MCP: Risk & Policy

WHAT IT DOES

What create_agent does on RetellAI MCP Server

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

WHY IT NEEDS A POLICY

Why create_agent needs a policy

This tool creates a new agent resource, which is a reversible write operation. However, the severity is rated 'high' because creating voice service agents could enable an AI agent to set up unauthorized voice automation systems, potentially for phishing, spoofing, or other malicious voice interactions.

From the tool's definition Tool name 'create_agent' and description 'Creates a new Retell agent' indicate creation of a new resource. In the context of RetellAI voice services, this creates a callable agent that can handle voice interactions.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_agent Rate-limited

create_agent 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": {
    "create_agent": {
      "limits": [
        {
          "counter": "create_agent_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 RetellAI MCP Server, so you can run agents against it safely.

FAQ

Questions about create_agent

What does the create_agent tool do? +

Creates a new Retell agent. It is categorised as a Write tool in the RetellAI 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 create_agent? +

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

What risk level is create_agent? +

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

Can I rate-limit create_agent? +

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

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

create_agent is provided by the RetellAI MCP Server MCP server (kuba2290/abhaybabbar_retellai-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.