AI agents use send-message to create or update resources in iMessage MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your iMessage MCP Server environment.
This tool sends iMessages/text messages to arbitrary phone numbers or email addresses. While technically reversible (messages can be deleted), the action creates new communications that persist in recipient inboxes and may have real-world consequences (phishing, impersonation, harassment).
From the tool's definition Tool name: 'send-message'; description: 'Send a text message to a phone number or email' — this creates and sends a new message, a reversible write action.
Documented attack patterns abuse exactly the kind of access send-message gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and iMessage MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for send-message:
{
"version": "1",
"default": "deny",
"tools": {
"send-message": {
"limits": [
{
"counter": "send-message_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}send-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.
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Send a text message to a phone number or email. It is categorised as a Write tool in the iMessage MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the iMessage MCP Server MCP server in PolicyLayer and add a rule for send-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 iMessage MCP Server. Nothing to install.
send-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-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-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-message is provided by the iMessage MCP Server MCP server (sameelarif/imessage-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from iMessage MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
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14 iMessage MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.