update_retell_llm · Retellai MCP: Risk & Policy

WHAT IT DOES

What update_retell_llm does on Retellai

AI agents use update_retell_llm 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 update_retell_llm needs a policy

This tool modifies existing Retell LLM configurations reversibly. It is not destructive (no deletion), not financial (no money movement), and not execute (no arbitrary code execution). It fits squarely in Write category. Severity is medium because misconfiguration of LLM parameters could affect call quality or AI behavior, but the change is reversible and the blast radius is limited to that specific LLM instance.

From the tool's definition Tool name 'update_retell_llm' and description 'Updates an existing Retell LLM' indicate modification of data. The verb 'update' is explicitly write-class operation that modifies but does not delete resources.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_retell_llm Rate-limited

update_retell_llm 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": {
    "update_retell_llm": {
      "limits": [
        {
          "counter": "update_retell_llm_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 update_retell_llm

What does the update_retell_llm tool do? +

Updates an existing Retell LLM. 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 update_retell_llm? +

Register the Retellai MCP server in PolicyLayer and add a rule for update_retell_llm: 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 update_retell_llm? +

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

Can I rate-limit update_retell_llm? +

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

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

update_retell_llm 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.