send_audio_message · Whatsapp MCP: Risk & Policy

WHAT IT DOES

What send_audio_message does on Whatsapp

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

WHY IT NEEDS A POLICY

Why send_audio_message needs a policy

This tool writes/creates new message data (audio) to WhatsApp conversations. It is reversible (messages can be deleted) and has no destructive or financial impact. Severity is medium because misuse could facilitate spam, harassment, or malicious audio distribution to WhatsApp users, but the blast radius is limited to message creation without affecting financial systems or causing irreversible data loss.

From the tool's definition Tool description states 'Send an audio file via URL or media ID' — a send action that creates a new message artifact in WhatsApp conversations.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

send_audio_message Rate-limited

send_audio_message 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": {
    "send_audio_message": {
      "limits": [
        {
          "counter": "send_audio_message_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 Whatsapp, so you can run agents against it safely.

FAQ

Questions about send_audio_message

What does the send_audio_message tool do? +

Send an audio file via URL or media ID. It is categorised as a Write tool in the Whatsapp MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on send_audio_message? +

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

What risk level is send_audio_message? +

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

Can I rate-limit send_audio_message? +

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

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

send_audio_message is provided by the Whatsapp MCP server (spirit122/whatsapp-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.