Polymarket MCP Server

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

With no annotations provided, the description carries full burden but offers limited behavioral insight. It mentions the HTTP method (POST) and endpoint (/prices), and that it returns {} if no prices found, but doesn't cover important aspects like rate limits, authentication needs, error handling, or what the successful response structure looks like (only the empty case is mentioned).

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 appropriately concise with three sentences that each serve a purpose: stating the tool's function, specifying the source of parameters, and providing an example. It's front-loaded with the core functionality, though the example could be slightly clearer.

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?

For a tool with no annotations and no output schema, the description is incomplete. It doesn't explain the response format for successful cases (only mentions the empty {} case), doesn't cover error conditions, rate limits, or authentication requirements. Given the complexity of a price-fetching tool in a financial context, more behavioral context is needed.

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 schema description coverage is 100%, so the schema already documents the 'token_ids' parameter thoroughly. The description adds minimal value beyond the schema by mentioning where to source token IDs and providing an example format, but doesn't explain parameter semantics like valid token ID formats or constraints beyond what's in the schema.

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: 'Batch prices via POST CLOB /prices' indicates it retrieves multiple prices through a specific API endpoint. It specifies the resource (prices) and verb (get/batch), though it doesn't explicitly differentiate from sibling tools like 'get_current_price' or 'get_batch_order_books' beyond mentioning the source of token IDs.

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 clear context for when to use this tool: it specifies that token IDs should come from 'list_active_markets or get_market_details' and shows an example format. However, it doesn't explicitly state when NOT to use it or mention alternatives like 'get_current_price' for single prices, though the batch nature is implied.

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