# Sports Rules (remote · sports-rules.gumballtools.com)

Work an offside call through IFAB Law 11 or NHL Rule 83, step by step.

- Trust score: 73/100 (medium)
- Change this week: +3
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-09-25

## Components

- remote · `sports-rules.gumballtools.com`: 73/100 (this document), [markdown](https://verifymcp.io/servers/com-gumballtools-sports-rules/api-mcp.md), [page](https://verifymcp.io/servers/com-gumballtools-sports-rules/api-mcp)

## Channel facts

- Endpoint: `https://sports-rules.gumballtools.com/api/mcp`
- Transports: `streamable-http`
- Auth: `none`
- Version: `0.1.0`

## 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 2026-09-25.

- **Endpoint Security**: 63/100
  - The endpoint's TLS certificate is valid, in date, and uses a strong key.
  - Authorisation not fully verified: no authorisation is required to call this server, and 2 tool(s) never declared a destructiveHint. The MCP spec treats an absent hint as destructive by default, so we cannot call this surface safe.
  - HTTPS is enforced; there's no plaintext access path.
  - The HSTS (Strict-Transport-Security) header is present.
  - DNSSEC check failed: this domain isn't protected by DNSSEC.
- **Transport & Reachability**: 100/100
  - Verified streamable-http transport via a live MCP handshake.
- **Schema Quality & AI Usability**: 58/100
  - AI-judged instruction clarity (excellent).
  - Context-footprint check failed: tool/resource definitions use about 1251 tokens (~625/item across 2 items; 2 tools + 0 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 67/100
  - Stability observed for 20 of 30 days with no destabilising changes; credit accrues until the full window elapses.
- **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.
- **Tool Safety**: 100/100
  - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.
  - We read all 2 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 2 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 Sports Rules MCP server?

Sports Rules is a hosted endpoint at https://sports-rules.gumballtools.com/api/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 com-gumballtools-sports-rules 'https://sports-rules.gumballtools.com/api/mcp'
```

### Cursor

```json
{
  "mcpServers": {
    "com-gumballtools-sports-rules": {
      "url": "https://sports-rules.gumballtools.com/api/mcp"
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "com-gumballtools-sports-rules": {
      "type": "http",
      "url": "https://sports-rules.gumballtools.com/api/mcp"
    }
  }
}
```

### Codex

```toml
[mcp_servers.com-gumballtools-sports-rules]
url = "https://sports-rules.gumballtools.com/api/mcp"
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "com-gumballtools-sports-rules": {
      "type": "remote",
      "url": "https://sports-rules.gumballtools.com/api/mcp",
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add com-gumballtools-sports-rules --url 'https://sports-rules.gumballtools.com/api/mcp' --transport streamable-http
```

### Hermes

```yaml
mcp_servers:
  com-gumballtools-sports-rules:
    url: "https://sports-rules.gumballtools.com/api/mcp"
```

### Netclaw

```json
{
  "McpServers": {
    "com-gumballtools-sports-rules": {
      "Transport": "http",
      "Url": "https://sports-rules.gumballtools.com/api/mcp"
    }
  }
}
```

### Vellum

```bash
assistant mcp add com-gumballtools-sports-rules -t streamable-http -u 'https://sports-rules.gumballtools.com/api/mcp'
```

### Other

```json
{
  "mcpServers": {
    "com-gumballtools-sports-rules": {
      "type": "http",
      "url": "https://sports-rules.gumballtools.com/api/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.

### 2026-09-25 (score 73, +1)

- [functional] We updated how we score, so this day's move reflects our rubric, not a change to the server

### 2026-09-22 (score 72, +1)

No change was recorded against any check on this day. Stability & Change Management went from 53 to 57. That category is still filling its 30-day observation window: 16 days of observed history at the previous scan, 17 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-09-20 (score 71, +1)

No change was recorded against any check on this day. Stability & Change Management went from 47 to 50. That category is still filling its 30-day observation window: 14 days of observed history at the previous scan, 15 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-09-18 (score 70, +1)

No change was recorded against any check on this day. Stability & Change Management went from 40 to 43. That category is still filling its 30-day observation window: 12 days of observed history at the previous scan, 13 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-09-16 (score 69, +1)

No change was recorded against any check on this day. Stability & Change Management went from 33 to 37. That category is still filling its 30-day observation window: 10 days of observed history at the previous scan, 11 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-09-14 (score 68, +1)

No change was recorded against any check on this day. Stability & Change Management went from 27 to 30. That category is still filling its 30-day observation window: 8 days of observed history at the previous scan, 9 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-09-12 (score 67, +1)

No change was recorded against any check on this day. Stability & Change Management went from 20 to 23. That category is still filling its 30-day observation window: 6 days of observed history at the previous scan, 7 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-09-10 (score 66, +1)

No change was recorded against any check on this day. Stability & Change Management went from 13 to 17. That category is still filling its 30-day observation window: 4 days of observed history at the previous scan, 5 at this one. The score rises as the window fills, whether or not the server changes.

## MCP tools (2)

### `offside` (~1134 tokens)

Work an offside call through IFAB Law 11 or NHL Rule 83

Work an offside call through the published decision procedure — association football under IFAB Law 11, or ice hockey under NHL Rule 83 — and return every step, not just the verdict.

Use this for any "was that offside" question in either sport. The two rules are structurally OPPOSITE and are routinely conflated, and there are four specific things that get answered wrong:

SOCCER:
1\. HANDS AND ARMS DO NOT COUNT, for anyone including goalkeepers. Only parts that could legally score are measured, and the boundary is the bottom of the armpit. This tool REFUSES to compute from an arm position rather than guessing where the shoulder was.
2\. AN OFFSIDE POSITION IS NOT AN OFFENCE. It becomes one only with involvement in active play. Do not report "he was offside" when the answer is that he was in an offside position and uninvolved. `involvement` is REQUIRED once the geometry makes it decisive — the tool errors rather than assuming, so ask the user what the player actually did, and pass "none" if the answer is nothing.
3\. No offside offence direct from a throw-in, goal kick, or corner. Absolute.
4\. A DELIBERATE play by an opponent resets it; a deflection or a save does NOT. This is the distinction most arguments turn on.

HOCKEY:
5\. SKATES decide it. Not the stick, not the body.
6\. Since 2021 a skate in the AIR above the blue line is still onside — the line is a plane, and ice contact is irrelevant. BUT this does not apply to tagging up on a delayed offside, where the skate must contact the line. Do not generalise the 2021 change to tag-ups.

Input for soccer: positions along the attacking axis in metres, larger being nearer the opponents’ goal line — `attacker`, `ball`, `secondLastDefender`. Any consistent scale works; only the order matters. Optionally `restart`, `foremostPart`, `inOwnHalf`, `involvement`, `lastTouch`.

Input for hockey: `rearSkate` in centimetres relative to the LEADING EDGE of the blue line, negative being the neutral-zone side. Optionally `skateOnIce`…

Input parameters:

- `attacker` (number): SOCCER. Position of the attacker along the attacking axis, larger being nearer the opponents’ goal line. Any consistent scale; only the order matters.
- `ball` (number): SOCCER. Position of the ball, same scale.
- `deliberatePlayCriteriaMet` (array): SOCCER. Which of IFAB’s five deliberate-play criteria are met. Reported, not scored — there is no pass mark.
- `foremostPart` (string): SOCCER. Which part the attacker position describes. Passing an arm or hand is REFUSED with an explanation: only parts that could legally score count, and the boundary is the bottom of the armpit.
- `inOwnHalf` (boolean): SOCCER. A player in their own half cannot be in an offside position.
- `involvement` (string): SOCCER. REQUIRED once the player is in an offside position — the call errors without it rather than assuming. An offside POSITION is not an offence; this is what turns it into one, and "none" is a co…
- `lastTouch` (string): SOCCER. A DELIBERATE play by an opponent resets offside. A deflection, a save, or a rebound off the frame does NOT.
- `rearSkate` (number): HOCKEY. The trailing skate in centimetres relative to the LEADING EDGE of the blue line — the edge nearer the attacking zone. Negative is the neutral-zone side; positive means it has broken the plane.
- `restart` (string): SOCCER. There is NO offside offence direct from a throw-in, goal kick, or corner. Always ask which restart it was before answering.
- `secondLastDefender` (number): SOCCER. Position of the SECOND-last opponent, same scale. Usually the last outfield defender, since the goalkeeper is normally the last.
- `situation` (string): HOCKEY. zone-entry (default), or tag-up for clearing a delayed offside. The same skate position can give opposite answers.
- `skateOnIce` (boolean): HOCKEY. Since 2021 this does NOT affect a zone entry — a skate above the plane is onside. It is decisive when tagging up, where the skate must contact the line.
- `sport` (string, required): Which rule book. The two are structurally opposite — do not mix them up.
- `stick` (number): HOCKEY. Ignored, and reported as ignored. Skates decide it.

### `offside_rule_contrast` (~117 tokens)

How soccer offside and hockey offside differ

Return the structural differences between soccer offside and hockey offside, dimension by dimension.

Use this when someone asks how the two compare, or when you are about to reason about one sport using an intuition from the other — which is the commonest way to get either wrong. They differ on what part of the player is measured, when the picture freezes, whether position alone is an offence, what happens at exactly level, what resets the situation, and which restarts are exempt.

Takes no arguments. Returns the comparison table.

## Diagnostics

Captured diagnostic sections: TLS, DNSSEC, Authorisation, Transports. The full working is on the page: https://verifymcp.io/servers/com-gumballtools-sports-rules/api-mcp#diagnostics

## Score history

- 2026-09-25: 73
- 2026-09-24: 72
- 2026-09-23: 72
- 2026-09-22: 72
- 2026-09-21: 71
- 2026-09-20: 71
- 2026-09-19: 70
- 2026-09-18: 70
- 2026-09-17: 69
- 2026-09-16: 69
- 2026-09-15: 68
- 2026-09-14: 68
- 2026-09-13: 67
- 2026-09-12: 67
- 2026-09-11: 66
- 2026-09-10: 66
- 2026-09-09: 65
- 2026-09-08: 65
- 2026-09-07: 65
- 2026-09-06: 64
- 2026-09-05: 64

## Common questions

### What is the Sports Rules MCP server?

Sports Rules is an MCP server listed in the public MCP registry as com.gumballtools/sports-rules. Work an offside call through IFAB Law 11 or NHL Rule 83, step by step. This page covers its hosted endpoint (https://sports-rules.gumballtools.com/api/mcp).

### Is the Sports Rules MCP server safe to use?

Sports Rules scores 73 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 Sports Rules MCP server expose?

Sports Rules exposes 2 tools: offside, offside_rule_contrast. Their descriptions and schemas cost roughly 1,251 tokens of context every time the server is loaded.

### Does the Sports Rules MCP server require authentication?

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

### Is the Sports Rules MCP server still maintained?

Sports Rules is still listed as active in the MCP registry. We last reached this channel on 25 September 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://sports-rules.gumballtools.com/api/mcp
- Repository: https://github.com/bwalvoord/gumball
- Website: https://sports-rules.gumballtools.com/
- Changelog RSS feed: https://verifymcp.io/servers/com-gumballtools-sports-rules/api-mcp.xml
- Changelog JSON feed: https://verifymcp.io/servers/com-gumballtools-sports-rules/api-mcp.json
- HTML version of this page: https://verifymcp.io/servers/com-gumballtools-sports-rules/api-mcp