custom_add_email_module · Marketo MCP Server MCP

WHAT IT DOES

What custom_add_email_module does on Marketo MCP Server

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

WHY IT NEEDS A POLICY

Why custom_add_email_module needs a policy

Adding an email module creates or modifies marketing assets in Marketo, which is reversible (modules can be removed or replaced). This is a Write operation rather than Execute because the tool itself is purpose-built for a specific API endpoint, not arbitrary code execution.

From the tool's definition Tool description states it 'Calls the Marketo REST API directly' to add an email module. The sibling tools (create_program, create_smart_campaign, approve_email_program) are Write operations that create or modify marketing assets.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

custom_add_email_module Rate-limited

custom_add_email_module 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": {
    "custom_add_email_module": {
      "limits": [
        {
          "counter": "custom_add_email_module_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 Marketo MCP Server, so you can run agents against it safely.

FAQ

Questions about custom_add_email_module

What does the custom_add_email_module tool do? +

[CUSTOM] Calls the Marketo REST API directly (not Adobe's native MCP). It is categorised as a Write tool in the Marketo 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 custom_add_email_module? +

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

What risk level is custom_add_email_module? +

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

Can I rate-limit custom_add_email_module? +

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

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

custom_add_email_module is provided by the Marketo MCP Server MCP server (tyron-pretorius/marketo-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.