update_template · Campaign Monitor MCP: Risk & Policy

WHAT IT DOES

What update_template does on Campaign Monitor MCP

AI agents use update_template 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 update_template needs a policy

This tool modifies email templates reversibly. While template updates could affect deployed campaigns if not carefully managed, the action itself is not destructive (templates can be reverted) and does not move money or execute arbitrary code. The blast radius is moderate—a malicious agent could alter templates to inject phishing content or malicious links affecting subscribers, but the change is recoverable.

From the tool's definition Tool name 'update_template' and description 'Update an existing email template' indicate modification of existing data without deletion or irreversible destruction.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_template Rate-limited

update_template 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": {
    "update_template": {
      "limits": [
        {
          "counter": "update_template_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 update_template

What does the update_template tool do? +

Update an existing email template. 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 update_template? +

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

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

Can I rate-limit update_template? +

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

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

update_template 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.