custom_is_member_of_list

[CUSTOM] Calls the Marketo REST API directly (not Adobe's native MCP).

SERVERMarketo MCP Server SOURCEtyron-pretorius/marketo-mcp

Low RISK CLASS

Category Read

Parameters 00 required

Recommended Allowedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/tyron-pretorius-marketo-mcp/custom-is-member-of-list.md

WHAT IT DOES

What custom_is_member_of_list does on Marketo MCP Server

AI agents call custom_is_member_of_list to retrieve information from Marketo MCP Server without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

RISK

Why custom_is_member_of_list is rated Low

The tool appears to query whether an entity (likely a lead) is a member of a specific list in Marketo. This is fundamentally a read operation that retrieves information without modifying or creating data. The 'is_member_of' pattern is typical for read-only membership checks.

From the tool's definition The tool name 'custom_is_member_of_list' indicates a query operation that checks membership status. The description states it 'Calls the Marketo REST API directly,' and in the context of sibling tools that include write/execute operations…

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs custom_is_member_of_list safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Marketo MCP Server, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For custom_is_member_of_list, this is the rule to start with:

custom_is_member_of_list Allowed

custom_is_member_of_list is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "custom_is_member_of_list": {}
  }
}

ALLOW ONLY THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Marketo MCP Server, apply this rule, and every custom_is_member_of_list call is checked against it from then on.

FAQ

Questions about custom_is_member_of_list

What does the custom_is_member_of_list tool do? +

[CUSTOM] Calls the Marketo REST API directly (not Adobe's native MCP). It is categorised as a Read tool in the Marketo MCP Server MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on custom_is_member_of_list? +

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

custom_is_member_of_list is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit custom_is_member_of_list? +

Yes. Add a rate_limit block to the custom_is_member_of_list 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_is_member_of_list completely? +

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

custom_is_member_of_list 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.

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