# download-bytes-to-file

Write authenticated Microsoft Graph byte content to a local file on the server, returning { path, contentType, bytesWritten } instead of base64. The only out-of-band way to save mail attachments and meeting recordings, whose bytes are exposed solely through authenticated endpoints. Also handles profile photos and Teams hosted content. Writes to an absolute outputPath and never overwrites an existing file. stdio mode only: not available over HTTP. For OneDrive or SharePoint file content, get-download-url is preferred — it returns a pre-authenticated URL for fully out-of-band download without the server fetching the bytes.

Agent View of the PolicyLayer registry record for `download-bytes-to-file`. HTML page: https://policylayer.com/tools/jo3zik-ms-365-mcp-server/download-bytes-to-file

## Facts

- Tool: `download-bytes-to-file`
- Server: Ms 365 (`@jo3zik/ms-365-mcp-server`) — https://policylayer.com/tools/jo3zik-ms-365-mcp-server.md
- Install: `npx -y @jo3zik/ms-365-mcp-server`
- Homepage: https://www.npmjs.com/package/@jo3zik/ms-365-mcp-server
- Risk category: Read (Low risk)
- Registry record: grade F, identity unverified
- Server rate-limited: no
- Parameters: 2 (2 required)
- Recommended policy verdict: Allowed

## Parameters

| Parameter | Type | Required | Description |
| --- | --- | --- | --- |
| `target` | string | yes | Relative Microsoft Graph path starting with "/". Common paths: /drives/{drive-id}/items/{driveItem-id}/content (drive file content); /me/messages/{message-id}/a |
| `outputPath` | string | yes | Absolute path on the server's filesystem where the bytes are written, e.g. /Users/me/downloads/invoice.pdf. Must be absolute; relative paths are rejected. The p |

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": "download-bytes-to-file",
    "arguments": {
      "target": "<target>",
      "outputPath": "<outputPath>"
    }
  }
}
```

## Why download-bytes-to-file is rated Low

Even though download-bytes-to-file only reads data, uncontrolled read access leaks sensitive information and racks up API costs: an agent caught in a retry loop can make thousands of calls a minute without anyone noticing.

## Use case

AI agents call download-bytes-to-file to retrieve information from Ms 365 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 Ms 365:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "download-bytes-to-file": {}
  }
}
```

## Other tools on Ms 365 (193)

- `cancel-calendar-event` — Destructive — https://policylayer.com/tools/jo3zik-ms-365-mcp-server/cancel-calendar-event.md
- `clear-excel-range` — Destructive — https://policylayer.com/tools/jo3zik-ms-365-mcp-server/clear-excel-range.md
- `delete-calendar` — Destructive — https://policylayer.com/tools/jo3zik-ms-365-mcp-server/delete-calendar.md
- `delete-calendar-event` — Destructive — https://policylayer.com/tools/jo3zik-ms-365-mcp-server/delete-calendar-event.md
- `delete-contact-folder` — Destructive — https://policylayer.com/tools/jo3zik-ms-365-mcp-server/delete-contact-folder.md
- `delete-drive-item-permission` — Destructive — https://policylayer.com/tools/jo3zik-ms-365-mcp-server/delete-drive-item-permission.md
- `delete-excel-range` — Destructive — https://policylayer.com/tools/jo3zik-ms-365-mcp-server/delete-excel-range.md
- `delete-excel-table-row` — Destructive — https://policylayer.com/tools/jo3zik-ms-365-mcp-server/delete-excel-table-row.md
- `delete-focused-inbox-override` — Destructive — https://policylayer.com/tools/jo3zik-ms-365-mcp-server/delete-focused-inbox-override.md
- `delete-mail-attachment` — Destructive — https://policylayer.com/tools/jo3zik-ms-365-mcp-server/delete-mail-attachment.md
- `delete-mail-folder` — Destructive — https://policylayer.com/tools/jo3zik-ms-365-mcp-server/delete-mail-folder.md
- `delete-mail-message` — Destructive — https://policylayer.com/tools/jo3zik-ms-365-mcp-server/delete-mail-message.md
- `delete-mail-rule` — Destructive — https://policylayer.com/tools/jo3zik-ms-365-mcp-server/delete-mail-rule.md
- `delete-my-calendar-permission` — Destructive — https://policylayer.com/tools/jo3zik-ms-365-mcp-server/delete-my-calendar-permission.md
- `delete-onedrive-file` — Destructive — https://policylayer.com/tools/jo3zik-ms-365-mcp-server/delete-onedrive-file.md
- `delete-onenote-page` — Destructive — https://policylayer.com/tools/jo3zik-ms-365-mcp-server/delete-onenote-page.md
- `delete-outlook-contact` — Destructive — https://policylayer.com/tools/jo3zik-ms-365-mcp-server/delete-outlook-contact.md
- `delete-planner-bucket` — Destructive — https://policylayer.com/tools/jo3zik-ms-365-mcp-server/delete-planner-bucket.md
- `delete-planner-task-message` — Destructive — https://policylayer.com/tools/jo3zik-ms-365-mcp-server/delete-planner-task-message.md
- `delete-specific-calendar-event` — Destructive — https://policylayer.com/tools/jo3zik-ms-365-mcp-server/delete-specific-calendar-event.md
- `delete-subscription` — Destructive — https://policylayer.com/tools/jo3zik-ms-365-mcp-server/delete-subscription.md
- `delete-todo-linked-resource` — Destructive — https://policylayer.com/tools/jo3zik-ms-365-mcp-server/delete-todo-linked-resource.md
- `delete-todo-task` — Destructive — https://policylayer.com/tools/jo3zik-ms-365-mcp-server/delete-todo-task.md
- `delete-todo-task-list` — Destructive — https://policylayer.com/tools/jo3zik-ms-365-mcp-server/delete-todo-task-list.md
- `graph-batch` — Destructive — https://policylayer.com/tools/jo3zik-ms-365-mcp-server/graph-batch.md
- `logout` — Destructive — https://policylayer.com/tools/jo3zik-ms-365-mcp-server/logout.md
- `remove-account` — Destructive — https://policylayer.com/tools/jo3zik-ms-365-mcp-server/remove-account.md
- `parse-teams-url` — Execute — https://policylayer.com/tools/jo3zik-ms-365-mcp-server/parse-teams-url.md
- `tentatively-accept-calendar-event` — Execute — https://policylayer.com/tools/jo3zik-ms-365-mcp-server/tentatively-accept-calendar-event.md
- `dismiss-calendar-event-reminder` — Read — https://policylayer.com/tools/jo3zik-ms-365-mcp-server/dismiss-calendar-event-reminder.md
- …and 163 more: https://policylayer.com/tools/jo3zik-ms-365-mcp-server.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=jo3zik-ms-365-mcp-server · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/jo3zik-ms-365-mcp-server