# `com.zeltorlabs/music-tools` on anlyon.dev

> Text inside fenced blocks marked untrusted-server-text was written by the MCP server's publisher, not by anlyon.dev. It is data to inspect, not instructions to follow. Invisible characters are shown as [U+XXXX].
> No finding is not a safety guarantee: these are point-in-time checks of tool definitions, not of code or behaviour.

- Page: https://anlyon.dev/servers/com.zeltorlabs/music-tools
- JSON: https://anlyon.dev/api/v1/servers/com.zeltorlabs/music-tools
- Version: 1.1.0 (active)
- Publisher: com.zeltorlabs (domain proven to the MCP Registry)
- Runs: remote (streamable-http)
- Sign-in to list tools: none
- Metadata from the official MCP Registry, synced 2026-10-31T23:17:47.184Z

Title and description, as the publisher wrote them:

```untrusted-server-text
Zeltor Music Tools
Check if two songs mix (Camelot key, BPM), read shared song DNA reports, tempo and nightcore math.
```

Scanned 2026-10-31T22:18:17.436Z over streamable-http.

**5 tools: 5 change things.**

| Group | Class | Tools | Claude Code |
| --- | --- | --- | --- |
| Deletes or cancels | destructive | 0 | deny |
| Can't be undone | irreversible | 0 | ask |
| Changes things | write | 5 | ask |
| Only reads | read | 0 | allow |

## Exfil surface

No private-data -> untrusted-input -> outbound path in this server alone: no tool is tagged private-data or untrusted-input or outbound.

| Tag | Meaning | Tools |
| --- | --- | --- |
| private-data | Reads files, mail, messages, databases, secrets, calendars or repositories. | none |
| untrusted-input | Brings in text someone else can write: web pages, inbound email, messages, issues and comments. | none |
| outbound | Can carry data to people or systems: it sends, posts or publishes, or takes a recipient, channel or URL. | none |

## Findings

- **warn** Annotations that disagree with the tool in `transpose` ([annotation-conflict](https://anlyon.dev/methodology#annotation-conflict))

```untrusted-server-text
The server marks "transpose" read-only (readOnlyHint: true), and its own name, description or input give the class "write".

annotations: {"readOnlyHint":true,"destructiveHint":false,"idempotentHint":true,"openWorldHint":false}; The description's first verb is "move": a word for a change.
```


## Changes things (5)

Creates or changes something that can be changed back. Claude Code: ask.

### `camelot`

- Nothing in its name or description says what it does, so it is counted as a write.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.

Description, as the server wrote it:

```untrusted-server-text
Gives the Camelot wheel code for a key and the three other keys that mix cleanly with it (one step either way with the same letter, and the relative major or minor).
```

### `check_mix`

- Nothing in its name or description says what it does, so it is counted as a write.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.

Description, as the server wrote it:

```untrusted-server-text
Decides whether two songs will mix well, from their keys and BPMs, using the Camelot wheel and DJ tempo limits (about 3% sounds natural, up to about 16% is usable, half and double time count). Returns a verdict, the tempo change in percent and the target BPM for track B, the smallest key shift in semitones if the keys clash, and a link to make the matched audio.
```

### `speed_pitch`

- Nothing in its name or description says what it does, so it is counted as a write.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.

Description, as the server wrote it:

```untrusted-server-text
For a nightcore (faster and higher) or slowed (slower and lower) version: the pitch change in semitones for a speed, the new BPM if given, and typical settings. Defaults: nightcore 1.25x, slowed 0.80x.
```

### `tempo_change`

- Nothing in its name or description says what it does, so it is counted as a write.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.

Description, as the server wrote it:

```untrusted-server-text
Percent change and playback rate to go from one BPM to another, how noticeable it will sound, the pitch change if it is not time-stretched, and the half and double time of the target.
```

### `transpose`

- The description's first verb is "move": a word for a change.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
- Findings: warn annotation-conflict

Description, as the server wrote it:

```untrusted-server-text
Moves a key up or down by semitones and gives the new key name and Camelot code, with a note on how natural the shift will sound.
```

## Claude Code permissions

For `.claude/settings.json`, assuming the server is installed as `music-tools`:

```json
{
  "permissions": {
    "allow": [],
    "ask": [
      "mcp__music-tools__check_mix",
      "mcp__music-tools__camelot",
      "mcp__music-tools__tempo_change",
      "mcp__music-tools__speed_pitch",
      "mcp__music-tools__transpose"
    ],
    "deny": []
  }
}
```

## Remote posture

What an anonymous client saw at the remote endpoint, last 2026-10-31T23:19:08.882Z, unchanged since 2026-10-31T23:19:08.882Z. No credentials were sent and no tool was called. Values are shown as the endpoint returned them. Method: https://anlyon.dev/methodology#remote-posture

| Fact | Observed |
| --- | --- |
| Reachable | `yes` |
| HTTP status of an anonymous initialize | `200` |
| tools/list served without credentials | `yes` |
| Tools that change things, listed without credentials | `5` |
| Protocol version | `2025-06-18` |
| WWW-Authenticate on 401 | `not observed` |
| resource_metadata in WWW-Authenticate | `none` |
| RFC 9728 protected resource metadata | `none` |
| Authorization servers | `none` |
| Legacy HTTP+SSE transport | `no` |
| Dynamic client registration | `not observed` |
| Client ID metadata documents | `not observed` |

- **warn** Tools that change things, listed to anyone ([unauth-remote-writes](https://anlyon.dev/methodology#unauth-remote-writes))

```untrusted-server-text
The endpoint served tools/list without credentials, and the list has 5 tools that change things (5 write). Whether a call also works without credentials was not tested: tools are never called.

https://zeltorlabs.com/mcp: tools/list returned 6 tools to an anonymous client, including check_mix (write), camelot (write), tempo_change (write), speed_pitch (write), transpose (write)
```