custom_upload_file

A write tool on the Marketo MCP server.

SERVERMarketo MCP Server SOURCEtyron-pretorius/marketo-mcp

Medium RISK CLASS

Category Write

Parameters 00 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/tyron-pretorius-marketo-mcp/custom-upload-file.md

WHAT IT DOES

What custom_upload_file does on Marketo MCP Server

AI agents use custom_upload_file 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.

RISK

Why custom_upload_file is rated Medium

The name implies a file upload operation, which is a Write action. However, the empty description significantly lowers confidence. Given the Marketo context (marketing assets like emails, images), this likely uploads files to Marketo's file storage. Severity is high because an AI agent could upload malicious or unintended content at scale.

From the tool's definition Tool name 'custom_upload_file' suggests uploading/writing file data; description is empty and uninformative.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs custom_upload_file 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_upload_file, this is the rule to start with:

custom_upload_file Rate-limited

custom_upload_file 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_upload_file": {
      "limits": [
        {
          "counter": "custom_upload_file_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT 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_upload_file call is checked against it from then on.

FAQ

Questions about custom_upload_file

What does the custom_upload_file tool do? +

custom_upload_file is a write tool on the Marketo MCP Server MCP server. 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_upload_file? +

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

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

Can I rate-limit custom_upload_file? +

Yes. Add a rate_limit block to the custom_upload_file 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_upload_file completely? +

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

custom_upload_file 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.

KEEP EXPLORING

More on Marketo MCP Server, and thousands of servers like it.

This server

All 298 Marketo MCP Server tools →

Across the catalogue

write_file on 0sec → The MCP Attack Database →

Guides

Govern customer-ops agents →Argument validation →Scoped token →