custom_update_email2 · Marketo MCP Server MCP: Risk & Policy

WHAT IT DOES

What custom_update_email2 does on Marketo MCP Server

AI agents invoke custom_update_email2 to trigger actions in Marketo MCP Server. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why custom_update_email2 needs a policy

The tool directly invokes the Marketo REST API with unspecified arguments. The name suggests email updating (Write), but because it calls the API 'directly' with no constraints described, it could execute arbitrary API operations including activating campaigns, modifying leads, or other high-impact actions. The most severe plausible category given the open-ended API access is Execute.

From the tool's definition 'Calls the Marketo REST API directly' — the tool makes direct REST API calls; name includes 'update_email' suggesting modification, but description is largely uninformative about exact operations or constraints

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

custom_update_email2 Rate-limited

custom_update_email2 stays usable, but rate-capped — a runaway agent can't fire it dozens of times 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_update_email2": {
      "limits": [
        {
          "counter": "custom_update_email2_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-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_update_email2

What does the custom_update_email2 tool do? +

[CUSTOM] Calls the Marketo REST API directly (not Adobe's native MCP). It is categorised as a Execute tool in the Marketo MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on custom_update_email2? +

Register the Marketo MCP Server MCP server in PolicyLayer and add a rule for custom_update_email2: 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_update_email2? +

custom_update_email2 is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit custom_update_email2? +

Yes. Add a rate_limit block to the custom_update_email2 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_update_email2 completely? +

Set action: deny in the PolicyLayer policy for custom_update_email2. 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_update_email2? +

custom_update_email2 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.