oddsrail

compare_venues

Read-onlyIdempotent

Identify corresponding Polymarket and Kalshi markets for the same event using title similarity and close-date proximity, producing candidate matches to evaluate further.

Instructions

Find markets that may be the SAME event on both Polymarket and Kalshi. NOT an arbitrage scanner: matches are candidates from title similarity plus a close-date check, and a price difference between two candidates is not profit. Identical wording does not mean identical resolution criteria — read both, and run quote_cost on each leg, before acting.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "query": "<query>"
    },
    "name": "compare_venues"
  }
}

Input Schema

Name	Required	Description	Default
`limit`	No
`query`	Yes
`min_similarity`	No
`max_close_days_apart`	No

Schema Changelog

Changes observed during successful MCP inspections.

Addedv0.18.1Sep 22, 2026

TDQS

A4.4/5.0

Behavior4/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and non-destructive behavior. The description adds useful behavioral context beyond this: the tool returns candidates based on title similarity and close-date, not verified matches, and identical wording does not imply identical resolution criteria. No contradiction with annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Three sentences, all purposeful and front-loaded: the primary purpose first, followed by a critical negative warning and an actionable caveat. There is no fluff or repetition.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a multi-venue comparison tool with no output schema and zero parameter descriptions, the description conveys the algorithm, the risk, and the recommended next steps. It is mostly sufficient, though it could more explicitly describe the expected output and each parameter's role.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, so the description must compensate. It hints at the meaning of min_similarity and max_close_days_apart via 'title similarity plus a close-date check,' but it does not explicitly explain the query parameter or the limit parameter. This is partial compensation, not full.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb and resource: 'Find markets that may be the SAME event on both Polymarket and Kalshi.' It also distinguishes itself from an arbitrage scanner, which helps differentiate it from related trading/quoting tools like quote_cost.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines5/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

It explicitly says what the tool is NOT ('NOT an arbitrage scanner') and gives a clear condition for correct use: matches are candidates, price differences are not profit, and users should read both resolution criteria and run quote_cost on each leg before acting. This provides actionable when-to-use and when-not-to-use guidance.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.