create_phone_number · Retellai MCP: Risk & Policy

WHAT IT DOES

What create_phone_number does on Retellai

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

WHY IT NEEDS A POLICY

Why create_phone_number needs a policy

This tool creates a new phone number resource, which is a Write operation—it modifies state by adding a new asset to the system. Severity is high because phone numbers can be used to conduct outbound calls or receive inbound communications, potentially enabling fraud, harassment, or spoofing if provisioned maliciously.

From the tool's definition Tool name 'create_phone_number' and description 'Creates a new phone number' indicate creation of a new resource that is reversible via deletion (delete_phone_number exists as a sibling tool).

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_phone_number Rate-limited

create_phone_number 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_phone_number": {
      "limits": [
        {
          "counter": "create_phone_number_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, so you can run agents against it safely.

FAQ

Questions about create_phone_number

What does the create_phone_number tool do? +

Creates a new phone number. It is categorised as a Write tool in the Retellai 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_phone_number? +

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

What risk level is create_phone_number? +

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

Can I rate-limit create_phone_number? +

Yes. Add a rate_limit block to the create_phone_number 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_number completely? +

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

create_phone_number is provided by the Retellai MCP server (@abhaybabbar/retellai-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.