graph-polymarket-mcp

get_market_open_interest

Retrieve top Polymarket markets ranked by open interest, showing USDC locked in outstanding positions. This tool accesses unique data from the Open Interest subgraph.

Instructions

Get the top Polymarket markets ranked by open interest (USDC locked in outstanding positions). This data is unique to the Open Interest subgraph — no other Polymarket subgraph tracks OI.

Tool call template

This tool declares no required parameters. Add optional parameters from the input schema as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {},
    "name": "get_market_open_interest"
  }
}

Input Schema

Name	Required	Description	Default
`first`	No	Number of markets to return (1-100)
`orderBy`	No	Field to rank markets by	amount
`orderDirection`	No	Sort direction	desc

Schema Changelog

Changes observed during successful MCP inspections.

Addedv2.0.0May 2, 2026

TDQS

C2.9/5.0

Behavior2/5

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

With no annotations, the description carries the full burden but only adds the meaning of open interest and subgraph uniqueness. It does not disclose ordering defaults, limits, return format, or any other behavioral traits. This is minimal disclosure for a query tool.

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?

The description is two concise sentences. The first gives the core purpose; the second adds relevant uniqueness context without waste. Every phrase earns its place.

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

Completeness2/5

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

Given no output schema and no annotations, the description should explain what is returned, but it does not mention the result structure or fields. It also lacks guidance on how to use the parameters in context. The moderate complexity and optional params are only partially addressed.

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?

The input schema has 100% description coverage, including defaults (first=10, orderBy=amount, orderDirection=desc) and valid enums. The description adds no parameter-specific information, but the schema is sufficient, so the baseline 3 applies.

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

Purpose4/5

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

The description clearly states the tool's function: 'Get the top Polymarket markets ranked by open interest' with a definition of OI. It is specific in verb and resource, though it does not explicitly contrast with sibling tools like get_global_open_interest or get_oi_history, so it falls just short of a 5.

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

Usage Guidelines2/5

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

No guidance is provided on when to use this tool versus alternatives such as get_global_open_interest for aggregate OI or get_oi_history for historical trends. The only contextual note is about subgraph uniqueness, which does not help an agent choose between related OI tools.

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