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 does well by disclosing key behavioral traits: it specifies the data source (CLOB/book depth), mentions the 404 error for inactive tokens, and provides an example token_id. It doesn't cover rate limits or authentication needs, but adds useful context beyond basic function.

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 sized with three sentences that each add value: stating the purpose, providing context/sources, and giving an error condition with example. It's front-loaded with the core function, though the structure could be slightly more polished for readability.

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 single-parameter tool with no annotations and no output schema, the description is moderately complete. It covers purpose, usage context, and error behavior, but lacks details on return format (e.g., what liquidity metrics are computed) and doesn't fully compensate for the missing output schema, leaving gaps for an agent.

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%, so the schema already documents the token_id parameter. The description adds marginal value by providing an example (token_id=clobTokenIds[0]) and mentioning token sources, but doesn't explain parameter semantics beyond what's implied in the schema. Baseline 3 is appropriate given high schema coverage.

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 computes liquidity from CLOB/book depth in USD, which is a specific verb+resource combination. However, it doesn't explicitly differentiate from sibling tools like 'get_order_book' or 'get_spread' that might also provide market data, leaving some ambiguity about uniqueness.

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 by mentioning token sources (list_active_markets or get_market_details) and the 404 error condition for inactive tokens. However, it lacks explicit guidance on when to use this tool versus alternatives like 'get_order_book' for raw data or 'get_spread' for price differences, leaving the agent to infer context.

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