cp · MCP File System Server MCP: Risk & Policy

WHAT IT DOES

What cp does on MCP File System Server

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

WHY IT NEEDS A POLICY

Why cp needs a policy

Copying a file or directory creates new data at the destination path. This is a reversible Write operation (the copy can be deleted). However, it could overwrite an existing file at the destination, which raises the severity slightly. It does not delete the source, so it is not Destructive. Severity is medium because misuse could silently overwrite important files at the destination path.

From the tool's definition 'Copy file or directory' — creates a new copy of existing data without removing the original

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

cp Rate-limited

cp 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": {
    "cp": {
      "limits": [
        {
          "counter": "cp_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 MCP File System Server, so you can run agents against it safely.

FAQ

Questions about cp

What does the cp tool do? +

Copy file or directory. It is categorised as a Write tool in the MCP File System 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 cp? +

Register the MCP File System Server MCP server in PolicyLayer and add a rule for cp: 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 MCP File System Server. Nothing to install.

What risk level is cp? +

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

Can I rate-limit cp? +

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

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

cp is provided by the MCP File System Server MCP server (kvas-it/mcp-server-fs). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.