# `com.sienasociety/siena` 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.sienasociety/siena
- JSON: https://anlyon.dev/api/v1/servers/com.sienasociety/siena
- Version: 1.0.0 (active)
- Publisher: com.sienasociety (domain proven to the MCP Registry)
- Runs: remote (streamable-http)
- Sign-in to list tools: none
- Metadata from the official MCP Registry, synced 2026-11-02T11:17:39.919Z

Title and description, as the publisher wrote them:

```untrusted-server-text
Siena Society
Find Siena friendship dinners in London: upcoming Thursdays, how it works, and the booking link.
```

Scanned 2026-11-02T10:18:04.098Z over streamable-http.

**5 tools: 1 change things and 4 only read.**

| Group | Class | Tools | Claude Code |
| --- | --- | --- | --- |
| Deletes or cancels | destructive | 0 | deny |
| Can't be undone | irreversible | 0 | ask |
| Changes things | write | 1 | ask |
| Only reads | read | 4 | allow |

## Exfil surface

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

| Tag | Meaning | Tools |
| --- | --- | --- |
| private-data | Reads files, mail, messages, databases, secrets, calendars or repositories. | `mcp__siena__get_dinner` |
| 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 `start_booking` ([annotation-conflict](https://anlyon.dev/methodology#annotation-conflict))

```untrusted-server-text
The server marks "start_booking" 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 name "start_booking" says "start": a word for a change.
```


## Changes things (1)

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

### `start_booking`

- The name "start_booking" says "start": 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
Returns the link where the person books a seat at a Siena dinner on sienasociety.com. It books nothing and charges nothing. On the website the person signs up or signs in, answers six short questions the first time, and pays for the seat. Never ask for card details or personal data in chat.
```

## Only reads (4)

Looks things up and changes nothing. Claude Code: allow.

### `get_dinner`

- The name "get_dinner" says "get": a word for reading.
- Tag private-data: The description's first sentence says "get" and "table": it reads databases.

Description, as the server wrote it:

```untrusted-server-text
Gets one Siena dinner in full: date and time, where it happens, table size, seat price, the booking window and the cancellation rule. The restaurant stays private until Siena emails it on the Wednesday before.
```

### `how_it_works`

- The description's first verb is "explain": a word for reading.

Description, as the server wrote it:

```untrusted-server-text
Explains how Siena friendship dinners work: sign-up, matching, the Wednesday email, the seat price and Premium, cancellation and refunds, and links to the policies.
```

### `list_cities`

- The name "list_cities" says "list": a word for reading.

Description, as the server wrote it:

```untrusted-server-text
Lists the cities where Siena runs friendship dinners, with the dinner night and time. Siena runs in London only today.
```

### `list_upcoming_dinners`

- The name "list_upcoming_dinners" says "list": a word for reading.

Description, as the server wrote it:

```untrusted-server-text
Lists upcoming Siena friendship dinners in a city between two dates, and says which ones are open to book. Siena holds one dinner a week, on Thursday at 7:30pm London time, for small groups of strangers who want to make friends. A few holiday Thursdays have no dinner, and the list leaves them out. Booking for a Thursday opens on the Wednesday two weeks before and closes on the Tuesday before at 23:59. With no dates, the tool lists the next 4 Thursdays. It lists up to 12 weeks ahead.
```

## Claude Code permissions

For `.claude/settings.json`, assuming the server is installed as `siena`:

```json
{
  "permissions": {
    "allow": [
      "mcp__siena__list_cities",
      "mcp__siena__list_upcoming_dinners",
      "mcp__siena__get_dinner",
      "mcp__siena__how_it_works"
    ],
    "ask": [
      "mcp__siena__start_booking"
    ],
    "deny": []
  }
}
```

Capability tags behind the rules (a read tagged outbound is asked about):

- `mcp__siena__get_dinner`: private-data