# Penguin Statistics (remote · mcp.penguin-stats.io)

Crowdsourced Arknights drop rates by stage and item, for the CN, US, JP and KR game servers

- Trust score: 71/100 (medium)
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-10-24

## Components

- remote · `mcp.penguin-stats.io`: 71/100 (this document), [markdown](https://verifymcp.io/servers/io-penguin-stats-penguin-stats/mcp.md), [page](https://verifymcp.io/servers/io-penguin-stats-penguin-stats/mcp)

## Channel facts

- Endpoint: `https://mcp.penguin-stats.io/mcp`
- Transports: `streamable-http`
- Auth: `none`
- Version: `1.0.0`

## Trust breakdown

How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. Scores are 0–100 per category. Scoring method: https://verifymcp.io/docs/scoring (what has changed: https://verifymcp.io/docs/scoring/changelog)

Scored 2026-10-24.

- **Endpoint Security**: 83/100
  - The endpoint's TLS certificate is valid, in date, and uses a strong key.
  - No authorisation is required to call this server. Every tool declares its destructiveHint and none is destructive, so open access doesn't expose one.
  - HTTPS is enforced; there's no plaintext access path.
  - The HSTS (Strict-Transport-Security) header is present.
  - DNSSEC is configured correctly; the domain's records validate against the full chain to the root.
- **Transport & Reachability**: 100/100
  - Verified streamable-http transport via a live MCP handshake.
- **Schema Quality & AI Usability**: 63/100
  - AI-judged instruction clarity (excellent).
  - Context-footprint check failed: tool/resource definitions use about 1971 tokens (~328/item across 6 items; 6 tools + 0 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 0/100
  - Stability check failed: schema churn in the 1 day we've observed: 0 tool removals, 3 breaking changes, 0 auth/transport breaks, 0 additions.
- **Tool Coverage**: 100/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 100% of tool parameters carry a description.
  - Structured output schemas are declared (100% of tools); any adoption earns full credit.
- **Tool Safety**: 75/100
  - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.
  - 0 of 1 tool(s) whose name or description implies an irreversible operation declare an MCP destructiveHint annotation; "get_item_drop_rates" implies "drop" and declares readOnlyHint instead, contradicting what its own name says it does.
  - An AI judge read all 7 captured unit(s) of tool text and found none that tries to manipulate the model reading it.
- **Capabilities**: 100/100
  - Implements a current MCP spec version (2026-07-28).

## Install

### How do I install the Penguin Statistics MCP server?

Penguin Statistics is a hosted endpoint at https://mcp.penguin-stats.io/mcp, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.

### Claude

```bash
claude mcp add --transport http io-penguin-stats-penguin-stats 'https://mcp.penguin-stats.io/mcp'
```

### Cursor

```json
{
  "mcpServers": {
    "io-penguin-stats-penguin-stats": {
      "url": "https://mcp.penguin-stats.io/mcp"
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "io-penguin-stats-penguin-stats": {
      "type": "http",
      "url": "https://mcp.penguin-stats.io/mcp"
    }
  }
}
```

### Codex

```toml
[mcp_servers.io-penguin-stats-penguin-stats]
url = "https://mcp.penguin-stats.io/mcp"
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "io-penguin-stats-penguin-stats": {
      "type": "remote",
      "url": "https://mcp.penguin-stats.io/mcp",
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add io-penguin-stats-penguin-stats --url 'https://mcp.penguin-stats.io/mcp' --transport streamable-http
```

### Hermes

```yaml
mcp_servers:
  io-penguin-stats-penguin-stats:
    url: "https://mcp.penguin-stats.io/mcp"
```

### Netclaw

```json
{
  "McpServers": {
    "io-penguin-stats-penguin-stats": {
      "Transport": "http",
      "Url": "https://mcp.penguin-stats.io/mcp"
    }
  }
}
```

### Vellum

```bash
assistant mcp add io-penguin-stats-penguin-stats -t streamable-http -u 'https://mcp.penguin-stats.io/mcp'
```

### Other

```json
{
  "mcpServers": {
    "io-penguin-stats-penguin-stats": {
      "type": "http",
      "url": "https://mcp.penguin-stats.io/mcp"
    }
  }
}
```

The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.

## Changelog

Every change recorded for this component, newest first. Days that predate change tracking, or that we cannot explain, say so: "we were watching and nothing happened" and "we were not watching" are different claims.

### 2026-10-24 (score 71, 0)

- [security regression] Stability: unverified → fail
- [security] The server rewrote its instructions, which are the text every model session reads
- [security] The server changed its declared name: penguin-stats → io.penguin-stats/penguin-stats
- [security] Tool “get_item_drop_rates” rewrote its description, which is the text the model reads
- [security] Tool “get_stage_drops” rewrote its description, which is the text the model reads
- [security] Tool “search_items” rewrote its description, which is the text the model reads
- [security] Tool “search_stages” rewrote its description, which is the text the model reads
- [functional regression] Schema quality: 254 → 328
- [functional regression] “get_item_drop_rates” made “server” required, so existing callers break
- [functional regression] “get_stage_drops” made “server” required, so existing callers break
- [functional regression] “list_events” made “server” required, so existing callers break
- [functional] Server version: v3.14.67 → 3.14.70
- [cosmetic] “get_item_drop_rates” reworded the description of “lang”
- [cosmetic] “get_item_drop_rates” reworded the description of “server”
- [cosmetic] “get_stage_drops” reworded the description of “lang”
- [cosmetic] “get_stage_drops” reworded the description of “server”
- [cosmetic] “list_events” reworded the description of “lang”
- [cosmetic] “list_events” reworded the description of “server”
- [cosmetic] “search_items” reworded the description of “lang”
- [cosmetic] “search_stages” reworded the description of “lang”
- [cosmetic] “search_stages” reworded the description of “server”

### 2026-10-23 (score 71)

First indexed and scored.

## MCP tools (6)

### `get_dataset_info` (~75 tokens)

Dataset info

Describes the Penguin Statistics drop data: what its numbers mean (times, quantity, drop rate, sanity per item, window), the game servers with their time zones and how fresh the data of each is, the caveats, the license and how to credit it. Call it when unsure how to read or cite the numbers.

Output parameters:

- `caveats` (null|array)
- `definitions` (object)
- `description` (string)
- `docs` (string): Documentation of the public API of Penguin Statistics
- `license` (string)
- `licenseUrl` (string)
- `name` (string)
- `openapi` (string): OpenAPI (Swagger 2.0) document of the public API
- `servers` (null|array)
- `source` (object)
- `website` (string)

### `get_item_drop_rates` (~478 tokens)

Item drop rates

Where to farm an item: ranks every stage of a game server that drops it, with sanity per item, drop rate (items per run), runs (times) and quantity. Use it for any question about where to get an item, its best or most efficient stage, or which of several stages to run for it: one call ranks every stage, so don't look stages up one by one with get_stage_drops (only a named stage left out of the top_n returned). By default the stages open now that still drop it, lowest sanity per item first; stages of fewer than 100 runs (lowSample) rank after the others, gachas and the recruitment (no sanity cost) last. sort_by=drop_rate ranks by rate instead; include_closed=true adds past events and ended drops. item_id takes the item's name in any language; search_items first only when the name may mean several items.

Input parameters:

- `include_closed` (boolean): false (default): only the stages open on the server now that still drop the item. true: also the stages of past events and the drops that ended, for history.
- `item_id` (string, required): Item ID, from search_items: 30012. A name or alias that only one item has works too: 固源岩, Orirock Cube
- `lang` (string): Language of the names in the result: the language the user writes in, zh, en, ja or ko (en for other languages, and if omitted).
- `server` (string, required): Game server the user plays on: CN (mainland China: 国服, 官服, B服), US (global, English: 国际服, 美服), JP (日服) or KR (韩服). Stages, events and drop rates differ by server. Use the server the user named or the…
- `sort_by` (string): sanity_per_item (default): the least sanity per item first. drop_rate: the most items per run first.
- `top_n` (integer): Most stages to return, 1 to 100. Default 10.

Output parameters:

- `dataAsOf` (string): When the drop data was calculated, RFC 3339 in UTC
- `definitions` (object)
- `includeClosed` (boolean)
- `item` (object)
- `note` (string)
- `returned` (integer)
- `rows` (null|array): The stages, in the order of sortBy
- `server` (string)
- `sortBy` (string)
- `source` (object)
- `totalStages` (integer): Stages that drop the item now (dropsNow), or all with includeClosed
- `truncated` (boolean): Whether top_n left out stages

### `get_stage_drops` (~319 tokens)

Stage drops

What one stage drops on a game server: each item with drop rate (items per run), sanity per item, runs (times) and quantity, highest rate first, then the items it no longer drops; with the sanity cost of the stage and whether it is open now. For questions about a given stage. To find where to farm an item, call get_item_drop_rates instead: one call ranks every stage that drops it. Takes the stage ID from search_stages (codes are shared by several stages); a code works too if only one stage on the server has it.

Input parameters:

- `lang` (string): Language of the names in the result: the language the user writes in, zh, en, ja or ko (en for other languages, and if omitted).
- `server` (string, required): Game server the user plays on: CN (mainland China: 国服, 官服, B服), US (global, English: 国际服, 美服), JP (日服) or KR (韩服). Stages, events and drop rates differ by server. Use the server the user named or the…
- `stage_id` (string, required): Stage ID, from search_stages: main_01-07. A code works too if only one stage on the server has it: 1-7

Output parameters:

- `dataAsOf` (string): When the drop data was calculated, RFC 3339 in UTC
- `definitions` (object)
- `note` (string)
- `rows` (null|array): The items the stage drops, highest rate first; then those of windows that ended (end not null), which it no longer drops, such as the bonus drops of past events
- `server` (string)
- `source` (object)
- `stage` (object)
- `truncated` (boolean): Whether items were left out, past 100

### `list_events` (~317 tokens)

List events

Lists the events (limited-time activities) of a game server: status now (open, upcoming or closed), open and close times, whether a rerun. By default the open and upcoming events with their stage IDs (for get_stage_drops), or the latest 3 if there are none; open_only=false lists every event, latest first, with stage counts only. The main story and the permanent side stories are not events.

Input parameters:

- `lang` (string): Language of the names in the result: the language the user writes in, zh, en, ja or ko (en for other languages, and if omitted).
- `limit` (integer): Most events to return, 1 to 50. Default 20.
- `open_only` (boolean): true (default): the events open or upcoming on the server, with their stages; if there are none, the latest 3. false: every event of the server, latest first, without their stages.
- `server` (string, required): Game server the user plays on: CN (mainland China: 国服, 官服, B服), US (global, English: 国际服, 美服), JP (日服) or KR (韩服). Stages, events and drop rates differ by server. Use the server the user named or the…

Output parameters:

- `events` (null|array)
- `note` (string)
- `now` (string): The time of the statuses, RFC 3339 in UTC
- `openOnly` (boolean)
- `server` (string)
- `source` (object)
- `truncated` (boolean): Whether limit left out older events

### `search_items` (~275 tokens)

Search items

Finds items (materials, battle records, chips, furniture, event items) by name in any language (zh, en, ja, ko), by alias or nickname (土块, 狗粮), by pinyin (guyuanyan) or by item ID, and returns their item IDs (get_item_drop_rates takes a name too; search first when unsure which item is meant) and names in every language. Best matches first: exact before prefix before substring, names before aliases. Several items can share an alias (石头 is each tier of Orirock): ambiguous is then true; ask the user which one is meant or decide by context. Items of other types (workshop-crafted materials such as D32 Steel, recruitment tags) are returned only when no listed item matches, with a note saying what they are.

Input parameters:

- `lang` (string): Language of the names in the result: the language the user writes in, zh, en, ja or ko (en for other languages, and if omitted).
- `limit` (integer): Most items to return, 1 to 25. Default 10.
- `query` (string, required): Name, alias, pinyin or ID of the item, in any language: 固源岩, Orirock Cube, 石头, guyuanyan or 30012

Output parameters:

- `ambiguous` (boolean): Whether several items match as well as the first (an alias of several items, such as 石头 for the four tiers of Orirock): ask which one is meant, or pick by context, rather than take the first
- `note` (string): Set when no item of a listed type matched and the results are items of other types: what those are
- `query` (string)
- `results` (null|array): The items found, best match first
- `source` (object)
- `truncated` (boolean): Whether more items match than the limit

### `search_stages` (~365 tokens)

Search stages

Finds stages by code (1-7, S2-12, YW-4; full-width characters work too), by stage ID (main_01-07), or by the name or ID of their zone (第十章, Under Tides), and returns their stage IDs (for get_stage_drops; to find the stages that drop an item, use get_item_drop_rates) with their zone, sanity cost and whether they are open on the server now. Codes are not unique: the standard and tough versions of a stage of the main story share them, as do an event, its rerun and the stages it left open for good. Best matches first (the code before the zone, exact before prefix before substring), then the stages open now, standard before tough, original before permanent before rerun. ambiguous is true when several stages share the best-matching code (not for the stages of a zone found by its name): ask the user which one is meant or decide by context.

Input parameters:

- `lang` (string): Language of the names in the result: the language the user writes in, zh, en, ja or ko (en for other languages, and if omitted).
- `limit` (integer): Most stages to return, 1 to 25. Default 10.
- `query` (string, required): Code or ID of the stage, or the name or ID of its zone, in any language: 1-7, S2-12, main_01-07, 第十章 or Under Tides
- `server` (string): Game server the user plays on: CN (China), US (global, English), JP (Japan) or KR (Korea). Default CN. The stages open there now rank first.

Output parameters:

- `ambiguous` (boolean): Whether several stages share the code (or ID) that matched best: the standard and tough versions of a stage, or an event, its rerun and the stage it left open; ask which one is meant, or pick by cont…
- `query` (string)
- `results` (null|array): The stages found, best match first
- `server` (string): Game server of openNow
- `source` (object)
- `truncated` (boolean): Whether more stages match than the limit

## Diagnostics

Captured diagnostic sections: TLS, DNSSEC, Authorisation, Transports. The full working is on the page: https://verifymcp.io/servers/io-penguin-stats-penguin-stats/mcp#diagnostics

## Score history

- 2026-10-24: 71
- 2026-10-23: 71

## Common questions

### What is the Penguin Statistics MCP server?

Penguin Statistics is an MCP server listed in the public MCP registry as io.penguin-stats/penguin-stats. Crowdsourced Arknights drop rates by stage and item, for the CN, US, JP and KR game servers. This page covers its hosted endpoint (https://mcp.penguin-stats.io/mcp).

### Is the Penguin Statistics MCP server safe to use?

Penguin Statistics scores 71 out of 100 on VerifyMCP. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.

### What tools does the Penguin Statistics MCP server expose?

Penguin Statistics exposes 6 tools: get_dataset_info, get_item_drop_rates, get_stage_drops, list_events, search_items, search_stages. Their descriptions and schemas cost roughly 1,829 tokens of context every time the server is loaded.

### Does the Penguin Statistics MCP server require authentication?

No. We connected to Penguin Statistics without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.

### Is the Penguin Statistics MCP server still maintained?

Penguin Statistics is still listed as active in the MCP registry. We last reached this channel on 24 October 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

## Links

- Remote endpoint: https://mcp.penguin-stats.io/mcp
- Repository: https://github.com/penguin-statistics/backend-next
- Website: https://mcp.penguin-stats.io/
- Changelog RSS feed: https://verifymcp.io/servers/io-penguin-stats-penguin-stats/mcp.xml
- Changelog JSON feed: https://verifymcp.io/servers/io-penguin-stats-penguin-stats/mcp.json
- HTML version of this page: https://verifymcp.io/servers/io-penguin-stats-penguin-stats/mcp