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 and discloses key behavioral traits: it specifies the data source (CLOB), return values (bid/ask/mid), error condition (404 if no active CLOB), and example usage. However, it lacks details on rate limits, authentication needs, or response format structure.

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 efficiently structured with three sentences: purpose statement, source/error conditions, and example. Every sentence adds essential information without redundancy, making it front-loaded and appropriately sized.

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 no annotations and no output schema, the description provides good context for a read-only price-fetching tool by covering purpose, usage, parameters, and error handling. However, it doesn't fully describe the return value format (e.g., structure of bid/ask/mid) or potential edge cases beyond the 404 error.

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?

Schema description coverage is 100%, providing full parameter documentation. The description adds minimal value beyond the schema by implying token_id should come from specific sources (list_active_markets or get_market_details) and giving an example, but doesn't explain parameter interactions or semantics further.

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 specific action ('Get CLOB /price for BUY/SELL and return bid/ask/mid') and resource (price data for a token), distinguishing it from siblings like get_batch_prices, get_market_details, or get_order_book by focusing on current price retrieval from a CLOB with bid/ask/mid outputs.

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?

It explicitly provides when to use this tool ('Source: clobTokenIds from list_active_markets or get_market_details') and when not to ('If token has no active CLOB/order book, returns 404'), with clear alternatives named (list_active_markets, get_market_details) for obtaining valid token IDs.

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