# compare_prob

Judge an external probability (e.g. a Polymarket/Kalshi price) against our sharp fair line — ONE call. Resolves the fixture, de-vigs the sharp book to a fair probability (power de-vig for 3-way 1x2), and reports the edge fair_prob − external_prob in percentage points, the ROI, and a verdict (good / marginal / no_edge). DETECTION ONLY: InferSports never ingests prediction-market data, sizes a stake, or picks — it gives you the sharp reference and the gap; the call is yours. Args: query: natural-language fixture, e.g. "France vs Argentina" or a single team. external_prob: the external implied probability for outcome, in (0,1). Pre-net it for the venue's fee/spread (e.g. a Polymarket YES ask of 0.55 → 0.55). market_type: "1x2" (default; the prediction-market-comparable moneyline), "asian_handicap" (only ±0.5 maps cleanly to a binary), or "totals". period: "full_time" (default) or "half_time". outcome: which leg the probability is for — home/draw/away (1x2), home/away (AH), over/under. external_label: optional source label echoed back, e.g. "polymarket" | "kalshi". sport: optional filter — "football" or "basketball". date: optional UTC date "YYYY-MM-DD" to disambiguate same-name fixtures. Read caveats before acting: a 1x2 fair is regulation 90-min (a prediction market that includes extra time / "to advance" is a different market); quarter/integer AH carries push mass. On an ambiguous query status is "ambiguous" — do not guess. status is "no_line" when no sharp fair is available to judge against.

Agent View of the PolicyLayer registry record for `compare_prob`. HTML page: https://policylayer.com/tools/dev-infersports-infersports/compare-prob

## Facts

- Tool: `compare_prob`
- Server: Infersports (`https://api.infersports.dev/mcp`) — https://policylayer.com/tools/dev-infersports-infersports.md
- Homepage: https://github.com/https://api.infersports.dev/mcp
- Risk category: Read (Low risk)
- Registry record: grade C, identity unverified
- Server auth posture: open
- Server rate-limited: no
- Parameters: 8 (2 required)
- Recommended policy verdict: Allowed

## Parameters

| Parameter | Type | Required | Description |
| --- | --- | --- | --- |
| `date` | object | no |  |
| `query` | string | yes |  |
| `sport` | object | no |  |
| `period` | string | no |  |
| `outcome` | string | no |  |
| `market_type` | string | no |  |
| `external_prob` | number | yes |  |
| `external_label` | object | no |  |

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": "compare_prob",
    "arguments": {
      "query": "<query>",
      "external_prob": 0
    }
  }
}
```

## Why compare_prob is rated Low

This tool retrieves and analyzes existing odds data to compare probabilities and calculate edges. It produces informational output (fair probability, ROI, verdict) for decision support but does not execute trades, place bets, move money, modify data, or trigger external financial actions. The emphasis on "DETECTION ONLY" and that "the call is yours" confirms the tool is purely analytical/advisory.

From the tool's own definition: "Tool description states 'DETECTION ONLY: InferSports never ingests prediction-market data, sizes a stake, or picks — it gives you the sharp reference and the gap'."

## Use case

AI agents call compare_prob to retrieve information from Infersports 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 Infersports:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "compare_prob": {}
  }
}
```

## Other tools on Infersports (16)

- `compare_lines` — Read — https://policylayer.com/tools/dev-infersports-infersports/compare-lines.md
- `explain_handicap` — Read — https://policylayer.com/tools/dev-infersports-infersports/explain-handicap.md
- `find_arbitrage` — Read — https://policylayer.com/tools/dev-infersports-infersports/find-arbitrage.md
- `find_match` — Read — https://policylayer.com/tools/dev-infersports-infersports/find-match.md
- `find_value` — Read — https://policylayer.com/tools/dev-infersports-infersports/find-value.md
- `get_match_odds` — Read — https://policylayer.com/tools/dev-infersports-infersports/get-match-odds.md
- `get_opening_line` — Read — https://policylayer.com/tools/dev-infersports-infersports/get-opening-line.md
- `get_result` — Read — https://policylayer.com/tools/dev-infersports-infersports/get-result.md
- `get_sharp_line` — Read — https://policylayer.com/tools/dev-infersports-infersports/get-sharp-line.md
- `list_bookmakers` — Read — https://policylayer.com/tools/dev-infersports-infersports/list-bookmakers.md
- `list_events` — Read — https://policylayer.com/tools/dev-infersports-infersports/list-events.md
- `list_results` — Read — https://policylayer.com/tools/dev-infersports-infersports/list-results.md
- `list_today_matches` — Read — https://policylayer.com/tools/dev-infersports-infersports/list-today-matches.md
- `match_info` — Read — https://policylayer.com/tools/dev-infersports-infersports/match-info.md
- `scan_slate` — Read — https://policylayer.com/tools/dev-infersports-infersports/scan-slate.md
- `score_prob` — Read — https://policylayer.com/tools/dev-infersports-infersports/score-prob.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=dev-infersports-infersports · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/dev-infersports-infersports