add_client_person · Campaign Monitor MCP: Risk & Policy

WHAT IT DOES

What add_client_person does on Campaign Monitor MCP

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

WHY IT NEEDS A POLICY

Why add_client_person needs a policy

This tool creates a new user account or grants access to an existing person within a client account. It is reversible (the person can be removed or permissions changed later), making it a Write operation rather than Execute or Destructive.

From the tool's definition Tool name 'add_client_person' and description 'Add a person to a client with a specified access level' indicate creation of a new user/person record with permission assignment.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

add_client_person Rate-limited

add_client_person 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": {
    "add_client_person": {
      "limits": [
        {
          "counter": "add_client_person_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 Campaign Monitor MCP, so you can run agents against it safely.

FAQ

Questions about add_client_person

What does the add_client_person tool do? +

Add a person to a client with a specified access level. It is categorised as a Write tool in the Campaign Monitor MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on add_client_person? +

Register the Campaign Monitor MCP server in PolicyLayer and add a rule for add_client_person: 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 Campaign Monitor MCP. Nothing to install.

What risk level is add_client_person? +

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

Can I rate-limit add_client_person? +

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

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

add_client_person is provided by the Campaign Monitor MCP server (pauliowest/cmon-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.