create_dir · Omni Fs MCP: Risk & Policy

WHAT IT DOES

What create_dir does on Omni Fs

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

WHY IT NEEDS A POLICY

Why create_dir needs a policy

Creating a directory modifies the file system state by adding a new entity. Unlike reads (list_files, read_file), this has side effects. Unlike destructive operations, it's reversible via remove_backend or directory deletion.

From the tool's definition Tool name 'create_dir' and description 'Create a directory on the specified backend' indicate it creates a new file system entity. This is a reversible write operation (directories can be deleted).

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_dir Rate-limited

create_dir 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": {
    "create_dir": {
      "limits": [
        {
          "counter": "create_dir_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 Omni Fs, so you can run agents against it safely.

FAQ

Questions about create_dir

What does the create_dir tool do? +

Create a directory on the specified backend. It is categorised as a Write tool in the Omni Fs MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on create_dir? +

Register the Omni Fs MCP server in PolicyLayer and add a rule for create_dir: 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 Omni Fs. Nothing to install.

What risk level is create_dir? +

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

Can I rate-limit create_dir? +

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

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

create_dir is provided by the Omni Fs MCP server (vaayne/omni-fs-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.