send_sms · SIMcloud MCP: Risk & Policy

WHAT IT DOES

What send_sms does on SIMcloud

AI agents invoke send_sms to trigger actions in SIMcloud. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

PARAMETERS

Parameter	Type	Required	Description
`message`	string	Yes	SMS message body.
`recipient`	string	Yes	Recipient number, for example +27821234567.

Parameters from the server's own tool schema.

WHY IT NEEDS A POLICY

Why send_sms needs a policy

Sending an SMS is an external operation with real-world side effects (a message is delivered to a recipient). It is not merely writing data to a database; it executes a communication action. Misuse could result in spam, phishing, or harassment at scale, making severity high.

From the tool's definition 'Queues an SMS to a recipient through the authenticated SIMcloud account' — triggers an external messaging operation

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

send_sms Rate-limited

send_sms stays usable, but rate-capped — a runaway agent can't fire it dozens of times 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_sms": {
      "limits": [
        {
          "counter": "send_sms_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches SIMcloud, so you can run agents against it safely.

FAQ

Questions about send_sms

What does the send_sms tool do? +

Queues an SMS to a recipient through the authenticated SIMcloud account. It is categorised as a Execute tool in the SIMcloud MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

What parameters does send_sms accept? +

send_sms accepts 2 parameters: message, recipient. Required: message, recipient. The full parameter table on this page comes from the server's own tool schema.

How do I enforce a policy on send_sms? +

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

What risk level is send_sms? +

send_sms is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit send_sms? +

Yes. Add a rate_limit block to the send_sms 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_sms completely? +

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

send_sms is provided by the SIMcloud MCP server (https://simcloud.co.za/api/mcp.php). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.