file_copy · M365 MCP: Risk & Policy

WHAT IT DOES

What file_copy does on M365

AI agents use file_copy to create or update resources in M365 — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your M365 environment.

WHY IT NEEDS A POLICY

Why file_copy needs a policy

File copying is a Write operation—it creates new data (duplicated files) reversibly. While not destructive or financial, the high severity reflects that an uncontrolled file_copy could duplicate sensitive documents across OneDrive accounts, potentially spreading confidential information or filling storage.

From the tool's definition Tool name 'file_copy' indicates copying/duplicating files in a Microsoft 365 context (likely OneDrive based on server capabilities). The empty description prevents full certainty, but the operation semantically involves creating new file copies.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

file_copy Rate-limited

file_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": {
    "file_copy": {
      "limits": [
        {
          "counter": "file_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 M365, so you can run agents against it safely.

FAQ

Questions about file_copy

What does the file_copy tool do? +

file_copy. It is categorised as a Write tool in the M365 MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on file_copy? +

Register the M365 MCP server in PolicyLayer and add a rule for file_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 M365. Nothing to install.

What risk level is file_copy? +

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

Can I rate-limit file_copy? +

Yes. Add a rate_limit block to the file_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 file_copy completely? +

Set action: deny in the PolicyLayer policy for file_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 file_copy? +

file_copy is provided by the M365 MCP server (robin-collins/m365-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.