send_campaign_preview · Campaign Monitor MCP: Risk & Policy

WHAT IT DOES

What send_campaign_preview does on Campaign Monitor MCP

AI agents use send_campaign_preview 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 send_campaign_preview needs a policy

The tool performs a write operation by creating and sending email messages. While it uses 'send', it is not destructive (emails can be unsent or ignored) and does not execute arbitrary code or move money.

From the tool's definition send_campaign_preview sends a preview of a campaign to email addresses. This creates and transmits email messages (writes/creates data), which is a reversible action that modifies the state of the email system by adding preview messages to recipients' inboxes.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

send_campaign_preview Rate-limited

send_campaign_preview 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": {
    "send_campaign_preview": {
      "limits": [
        {
          "counter": "send_campaign_preview_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 send_campaign_preview

What does the send_campaign_preview tool do? +

Send a preview of a campaign to one or more email addresses. 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 send_campaign_preview? +

Register the Campaign Monitor MCP server in PolicyLayer and add a rule for send_campaign_preview: 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 send_campaign_preview? +

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

Can I rate-limit send_campaign_preview? +

Yes. Add a rate_limit block to the send_campaign_preview 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_campaign_preview completely? +

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

send_campaign_preview 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.