# list_directory_with_sizes

Get a detailed listing of all files and directories in a specified path, including sizes. Results clearly distinguish between files and directories with [FILE] and [DIR] prefixes. This tool is useful for understanding directory structure and finding specific files within a directory. Only works within allowed directories.

Agent View of the PolicyLayer registry record for `list_directory_with_sizes`. HTML page: https://policylayer.com/tools/filesystem/list-directory-with-sizes

## Facts

- Tool: `list_directory_with_sizes`
- Server: Filesystem (`@modelcontextprotocol/server-filesystem`) — https://policylayer.com/tools/filesystem.md
- Install: `npx -y @modelcontextprotocol/server-filesystem`
- Homepage: https://github.com/modelcontextprotocol/server-filesystem
- Risk category: Read (Low risk)
- Registry record: grade D, identity verified
- Server rate-limited: no
- Parameters: 2 (1 required)
- Recommended policy verdict: Allowed

## Parameters

| Parameter | Type | Required | Description |
| --- | --- | --- | --- |
| `path` | string | yes |  |
| `sortBy` | string | no | Sort entries by name or size |

Parameters from the server's own tool schema.

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "list_directory_with_sizes",
    "arguments": {
      "path": "<path>"
    }
  }
}
```

## Why list_directory_with_sizes is rated Low

This tool queries and returns metadata about files and directories (names, sizes, types) without any side effects. It performs directory traversal and information retrieval, which are characteristic of Read category tools. There is no modification, deletion, execution, or financial activity involved.

From the tool's own definition: "Tool description states it 'Get[s] a detailed listing of all files and directories' and is 'useful for understanding directory structure and finding specific files within a directory.' These are read-only operations that retrieve information without…"

Risk signals: Accepts file system path (path) · Bulk/mass operation — affects multiple targets

## Use case

AI agents call list_directory_with_sizes to retrieve information from Filesystem without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

## Recommended policy (PolicyLayer)

Verdict: **Allowed**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Filesystem:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "list_directory_with_sizes": {}
  }
}
```

## Other tools on Filesystem (13)

- `directory_tree` — Read — https://policylayer.com/tools/filesystem/directory-tree.md
- `get_file_info` — Read — https://policylayer.com/tools/filesystem/get-file-info.md
- `list_allowed_directories` — Read — https://policylayer.com/tools/filesystem/list-allowed-directories.md
- `list_directory` — Read — https://policylayer.com/tools/filesystem/list-directory.md
- `read_file` — Read — https://policylayer.com/tools/filesystem/read-file.md
- `read_media_file` — Read — https://policylayer.com/tools/filesystem/read-media-file.md
- `read_multiple_files` — Read — https://policylayer.com/tools/filesystem/read-multiple-files.md
- `read_text_file` — Read — https://policylayer.com/tools/filesystem/read-text-file.md
- `search_files` — Read — https://policylayer.com/tools/filesystem/search-files.md
- `create_directory` — Write — https://policylayer.com/tools/filesystem/create-directory.md
- `edit_file` — Write — https://policylayer.com/tools/filesystem/edit-file.md
- `move_file` — Write — https://policylayer.com/tools/filesystem/move-file.md
- `write_file` — Write — https://policylayer.com/tools/filesystem/write-file.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

---

Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=filesystem · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/filesystem