ftp_copy · Ftp MCP: Risk & Policy

WHAT IT DOES

What ftp_copy does on Ftp

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

WHY IT NEEDS A POLICY

Why ftp_copy needs a policy

ftp_copy performs file duplication on a remote server, which is a reversible modification operation (Write category). While it doesn't delete data, the blast radius is high because an AI agent could maliciously duplicate large files to consume disk space, duplicate sensitive files to unintended locations, or exhaust storage resources.

From the tool's definition Tool description states 'duplicate a file on the remote server' which creates a new copy of data. The tool modifies the remote filesystem by adding content (a duplicate file), making it a write operation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

ftp_copy Rate-limited

ftp_copy 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": {
    "ftp_copy": {
      "limits": [
        {
          "counter": "ftp_copy_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 Ftp, so you can run agents against it safely.

FAQ

Questions about ftp_copy

What does the ftp_copy tool do? +

Directly duplicate a file on the remote server without downloading and re-uploading. CRITICAL: Only supported on SFTP connections. It is categorised as a Write tool in the Ftp MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on ftp_copy? +

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

What risk level is ftp_copy? +

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

Can I rate-limit ftp_copy? +

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

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

ftp_copy is provided by the Ftp MCP server (kynlos/ftp-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.