Polymarket MCP Server

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It mentions the API endpoint and example return structure ('returns {marketTypes:[...]}'), but lacks details on authentication needs, rate limits, error handling, or whether this is a read-only operation. For a tool with zero annotation coverage, this leaves significant gaps in understanding its behavior.

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

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

The description is concise and front-loaded, with two sentences that directly state the purpose and provide a usage example. There's no unnecessary information, though it could be slightly more structured by separating the example into a distinct guideline.

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

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

Given the tool has no parameters, no annotations, and no output schema, the description is moderately complete. It covers the purpose and gives a usage hint, but lacks behavioral details like response format beyond the basic example, error cases, or integration context. For a simple read operation, this is adequate but with clear gaps.

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

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

The input schema has 0 parameters with 100% coverage, so no parameter documentation is needed. The description appropriately doesn't discuss parameters, focusing instead on the tool's purpose and usage. This meets the baseline for tools with no parameters.

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

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

The description clearly states the tool's purpose: 'Get valid sports market types from Gamma API /sports/market-types'. It specifies the verb ('Get'), resource ('valid sports market types'), and source ('Gamma API'), but doesn't explicitly differentiate from sibling tools like 'get_sports_metadata' or 'get_all_tags', which might also retrieve metadata-related information.

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

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

The description provides implied usage guidance with 'Example: use result in sports filters.', suggesting this tool is for obtaining data to filter sports markets. However, it doesn't explicitly state when to use this tool versus alternatives like 'get_sports_metadata' or 'filter_markets_by_category', nor does it mention any prerequisites or exclusions.

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