# filesystem_set_permissions

Set UNIX permissions on a file or directory. Can optionally apply recursively and strip existing ACLs.

Agent View of the PolicyLayer registry record for `filesystem_set_permissions`. HTML page: https://policylayer.com/tools/spranab-truenas-mcp/filesystem-set-permissions

## Facts

- Tool: `filesystem_set_permissions`
- Server: Truenas (`spranab/truenas-mcp`) — https://policylayer.com/tools/spranab-truenas-mcp.md
- Homepage: https://github.com/spranab/truenas-mcp
- Risk category: Write (Medium risk)
- Registry record: grade F, identity unverified
- Server rate-limited: no
- Parameters: 0
- Recommended policy verdict: Rate-limited

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

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "filesystem_set_permissions",
    "arguments": {}
  }
}
```

## Why filesystem_set_permissions is rated Medium

This tool modifies file and directory permissions, which are write operations that change system state. While permission changes are technically reversible (can be undone by resetting to previous values), the impact is significant—incorrect permission assignments could lock out legitimate users or expose sensitive data.

From the tool's own definition: "Tool description states it 'Set[s] UNIX permissions on a file or directory' and can 'apply recursively and strip existing ACLs'. This modifies filesystem metadata and access control configurations, which are reversible but impactful changes."

## Use case

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

## Recommended policy (PolicyLayer)

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

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "filesystem_set_permissions": {
      "limits": [
        {
          "counter": "filesystem_set_permissions_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}
```

## Other tools on Truenas (278)

- `acme_dns_authenticator_delete` — Destructive — https://policylayer.com/tools/spranab-truenas-mcp/acme-dns-authenticator-delete.md
- `alertservice_delete` — Destructive — https://policylayer.com/tools/spranab-truenas-mcp/alertservice-delete.md
- `api_key_delete` — Destructive — https://policylayer.com/tools/spranab-truenas-mcp/api-key-delete.md
- `app_delete` — Destructive — https://policylayer.com/tools/spranab-truenas-mcp/app-delete.md
- `app_rollback` — Destructive — https://policylayer.com/tools/spranab-truenas-mcp/app-rollback.md
- `boot_attach_disk` — Destructive — https://policylayer.com/tools/spranab-truenas-mcp/boot-attach-disk.md
- `boot_detach_disk` — Destructive — https://policylayer.com/tools/spranab-truenas-mcp/boot-detach-disk.md
- `bootenv_delete` — Destructive — https://policylayer.com/tools/spranab-truenas-mcp/bootenv-delete.md
- `certificate_delete` — Destructive — https://policylayer.com/tools/spranab-truenas-mcp/certificate-delete.md
- `cloud_backup_abort` — Destructive — https://policylayer.com/tools/spranab-truenas-mcp/cloud-backup-abort.md
- `cloud_backup_delete` — Destructive — https://policylayer.com/tools/spranab-truenas-mcp/cloud-backup-delete.md
- `cloudsync_credentials_delete` — Destructive — https://policylayer.com/tools/spranab-truenas-mcp/cloudsync-credentials-delete.md
- `cloudsync_delete` — Destructive — https://policylayer.com/tools/spranab-truenas-mcp/cloudsync-delete.md
- `cronjob_delete` — Destructive — https://policylayer.com/tools/spranab-truenas-mcp/cronjob-delete.md
- `dataset_delete` — Destructive — https://policylayer.com/tools/spranab-truenas-mcp/dataset-delete.md
- `directory_services_leave` — Destructive — https://policylayer.com/tools/spranab-truenas-mcp/directory-services-leave.md
- `disk_wipe` — Destructive — https://policylayer.com/tools/spranab-truenas-mcp/disk-wipe.md
- `group_delete` — Destructive — https://policylayer.com/tools/spranab-truenas-mcp/group-delete.md
- `initshutdown_delete` — Destructive — https://policylayer.com/tools/spranab-truenas-mcp/initshutdown-delete.md
- `iscsi_extent_delete` — Destructive — https://policylayer.com/tools/spranab-truenas-mcp/iscsi-extent-delete.md
- `iscsi_initiator_delete` — Destructive — https://policylayer.com/tools/spranab-truenas-mcp/iscsi-initiator-delete.md
- `iscsi_portal_delete` — Destructive — https://policylayer.com/tools/spranab-truenas-mcp/iscsi-portal-delete.md
- `iscsi_target_delete` — Destructive — https://policylayer.com/tools/spranab-truenas-mcp/iscsi-target-delete.md
- `iscsi_targetextent_delete` — Destructive — https://policylayer.com/tools/spranab-truenas-mcp/iscsi-targetextent-delete.md
- `keychaincredential_delete` — Destructive — https://policylayer.com/tools/spranab-truenas-mcp/keychaincredential-delete.md
- `network_interface_delete` — Destructive — https://policylayer.com/tools/spranab-truenas-mcp/network-interface-delete.md
- `network_rollback_changes` — Destructive — https://policylayer.com/tools/spranab-truenas-mcp/network-rollback-changes.md
- `network_static_route_delete` — Destructive — https://policylayer.com/tools/spranab-truenas-mcp/network-static-route-delete.md
- `nfs_share_delete` — Destructive — https://policylayer.com/tools/spranab-truenas-mcp/nfs-share-delete.md
- `pool_export` — Destructive — https://policylayer.com/tools/spranab-truenas-mcp/pool-export.md
- …and 248 more: https://policylayer.com/tools/spranab-truenas-mcp.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=spranab-truenas-mcp · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/spranab-truenas-mcp