AI agents use send_text_message to create or update resources in WhatsApp Cloud API MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your WhatsApp Cloud API MCP Server environment.
Sending messages is a reversible Write operation—messages can be deleted or unsent in most messaging platforms. It has moderate blast radius: an agent could spam users, send phishing content, or impersonate the account holder, but it does not permanently destroy data, execute arbitrary code, or transfer funds.
From the tool's definition Tool named 'send_text_message' with sibling tools 'send_template_message' on a WhatsApp Cloud API server that 'Enables AI agents to send WhatsApp messages'.
Documented attack patterns abuse exactly the kind of access send_text_message gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and WhatsApp Cloud API MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for send_text_message:
{
"version": "1",
"default": "deny",
"tools": {
"send_text_message": {
"limits": [
{
"counter": "send_text_message_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}send_text_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.
Free to start. No card required.
send_text_message. It is categorised as a Write tool in the WhatsApp Cloud API MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the WhatsApp Cloud API MCP Server MCP server in PolicyLayer and add a rule for send_text_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 Cloud API MCP Server. Nothing to install.
send_text_message is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the send_text_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.
Set action: deny in the PolicyLayer policy for send_text_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.
send_text_message is provided by the WhatsApp Cloud API MCP Server MCP server (mmarqueti/whatsapp-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from WhatsApp Cloud API MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
4 WhatsApp Cloud API MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.