retell_create_phone_call · Retell AI MCP Server MCP

WHAT IT DOES

What retell_create_phone_call does on Retell AI MCP Server

AI agents invoke retell_create_phone_call to trigger actions in Retell AI 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 retell_create_phone_call needs a policy

This tool triggers an external real-world operation — an outbound phone call — whose effects depend on the arguments (target number, agent config). It is not merely writing data; it causes an immediate, externally-observable action (a phone call being placed). Misuse could result in unwanted calls to arbitrary numbers at scale, making severity high.

From the tool's definition Create a new outbound phone call... Initiates a call from a registered phone number to a target number using a configured AI agent.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

retell_create_phone_call Rate-limited

retell_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": {
    "retell_create_phone_call": {
      "limits": [
        {
          "counter": "retell_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 Retell AI MCP Server, so you can run agents against it safely.

FAQ

Questions about retell_create_phone_call

What does the retell_create_phone_call tool do? +

Create a new outbound phone call using Retell AI. Initiates a call from a registered phone number to a target number using a configured AI agent. It is categorised as a Execute tool in the Retell AI 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 retell_create_phone_call? +

Register the Retell AI MCP Server MCP server in PolicyLayer and add a rule for retell_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 Retell AI MCP Server. Nothing to install.

What risk level is retell_create_phone_call? +

retell_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 retell_create_phone_call? +

Yes. Add a rate_limit block to the retell_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 retell_create_phone_call completely? +

Set action: deny in the PolicyLayer policy for retell_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 retell_create_phone_call? +

retell_create_phone_call is provided by the Retell AI MCP Server MCP server (itsanamune/retellsimp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.