create_customer · Rebillia MCP Server MCP: Risk & Policy

WHAT IT DOES

What create_customer does on Rebillia MCP Server

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

WHY IT NEEDS A POLICY

Why create_customer needs a policy

This tool creates new customer records in the billing system. While creation is reversible (customers can typically be deleted or deactivated), it modifies the customer database and could enable fraud, identity spoofing, or creation of fake accounts if misused by an agent without proper validation.

From the tool's definition Tool creates a new customer record via POST /customers endpoint. The description explicitly states it creates a new customer with required fields (firstName, lastName, email) and optional fields (businessName, locale, phoneNum, etc.).

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_customer Rate-limited

create_customer 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": {
    "create_customer": {
      "limits": [
        {
          "counter": "create_customer_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 Rebillia MCP Server, so you can run agents against it safely.

FAQ

Questions about create_customer

What does the create_customer tool do? +

Create a new customer. POST /customers. Required: firstName, lastName, email. Optional: businessName, locale, phoneNum, phoneExt, preferredCurrency, taxExempt. It is categorised as a Write tool in the Rebillia MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on create_customer? +

Register the Rebillia MCP Server MCP server in PolicyLayer and add a rule for create_customer: 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 Rebillia MCP Server. Nothing to install.

What risk level is create_customer? +

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

Can I rate-limit create_customer? +

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

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

create_customer is provided by the Rebillia MCP Server MCP server (rhinosaas/rebillia-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.