mass_duplicate · Melo MCP: Risk & Policy

WHAT IT DOES

What mass_duplicate does on Melo

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

WHY IT NEEDS A POLICY

Why mass_duplicate needs a policy

This tool creates new instances by duplicating existing ones, which is a reversible write operation. It does not delete or overwrite existing data, execute code, or involve financial transactions. The blast radius is medium because mass duplication could create large numbers of unwanted instances in a Roblox project, but the operation is reversible (duplicates can be deleted).

From the tool's definition Duplicate instances with automatic naming and optional position offsets. Returns: Array of new instance paths.

Risk signalsBulk/mass operation — affects multiple targets

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

mass_duplicate Rate-limited

mass_duplicate 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": {
    "mass_duplicate": {
      "limits": [
        {
          "counter": "mass_duplicate_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 Melo, so you can run agents against it safely.

FAQ

Questions about mass_duplicate

What does the mass_duplicate tool do? +

Duplicate instances with automatic naming and optional position offsets. Args: - paths (string[]): Instances to duplicate - count (number, optional): Number of copies per instance (default: 1) - offset (array, optional): [x, y, z] position offset between copies Returns: Array of new instance paths. It is categorised as a Write tool in the Melo MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on mass_duplicate? +

Register the Melo MCP server in PolicyLayer and add a rule for mass_duplicate: 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 Melo. Nothing to install.

What risk level is mass_duplicate? +

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

Can I rate-limit mass_duplicate? +

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

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

mass_duplicate is provided by the Melo MCP server (yannyhl/linkedsword-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.