fs_add_allowed_directory · LocalAnt MCP: Risk & Policy

WHAT IT DOES

What fs_add_allowed_directory does on LocalAnt

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

WHY IT NEEDS A POLICY

Why fs_add_allowed_directory needs a policy

This tool modifies the filesystem access control policy by adding directories to a whitelist. While not destructive (the change is reversible via removal), it is a Write operation that alters security permissions.

From the tool's definition Tool name 'fs_add_allowed_directory' and description 'Add a directory to the filesystem allowlist' indicate creation/modification of the allowlist configuration.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

fs_add_allowed_directory Rate-limited

fs_add_allowed_directory 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": {
    "fs_add_allowed_directory": {
      "limits": [
        {
          "counter": "fs_add_allowed_directory_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 LocalAnt, so you can run agents against it safely.

FAQ

Questions about fs_add_allowed_directory

What does the fs_add_allowed_directory tool do? +

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

How do I enforce a policy on fs_add_allowed_directory? +

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

What risk level is fs_add_allowed_directory? +

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

Can I rate-limit fs_add_allowed_directory? +

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

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

fs_add_allowed_directory is provided by the LocalAnt MCP server (yuga-hashimoto/localant). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.