create_phone_call · RetellAI MCP Server MCP: Risk & Policy

WHAT IT DOES

What create_phone_call does on RetellAI MCP Server

AI agents invoke create_phone_call to trigger actions in RetellAI MCP Server. 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 create_phone_call needs a policy

Initiating a phone call is an external operation with real-world effects (telephony resources are consumed, a call is placed to a real number). It goes beyond a simple write/data-creation action because it triggers an outbound communication event. Misuse could result in harassment, unwanted calls, or significant service charges, warranting a high severity rating.

From the tool's definition Creates a new phone call

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_phone_call Rate-limited

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

FAQ

Questions about create_phone_call

What does the create_phone_call tool do? +

Creates a new phone call. It is categorised as a Execute tool in the RetellAI MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on create_phone_call? +

Register the RetellAI MCP Server MCP server in PolicyLayer and add a rule for create_phone_call: 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_phone_call? +

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

Can I rate-limit create_phone_call? +

Yes. Add a rate_limit block to the create_phone_call 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_phone_call completely? +

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

create_phone_call 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.