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 that 'If no history, returns history=[]', which is useful, but fails to describe other critical behaviors such as rate limits, authentication requirements, error handling, or the format of returned data. For a tool with no annotations, this leaves significant gaps in understanding its operational traits.

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, starting with the core purpose. The additional sentences about sources, empty returns, and an example are relevant and add value without unnecessary verbosity. However, the structure could be slightly improved by explicitly separating guidelines from examples.

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 complexity (5 parameters, no annotations, no output schema), the description is incomplete. It doesn't explain the output format, error conditions, or behavioral details like pagination or data freshness. While it covers basic usage, it falls short for a tool that retrieves historical data, where such context is crucial for effective use.

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%, meaning the input schema already documents all parameters thoroughly. The description adds minimal value beyond the schema by providing an example ('Example: token_id=clobTokenIds[0], interval=1h'), which clarifies usage but doesn't elaborate on parameter meanings or constraints. This meets the baseline for 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's purpose: 'Get historical price data for a token.' It specifies the verb ('Get') and resource ('historical price data for a token'), making the intent unambiguous. However, it doesn't explicitly differentiate from sibling tools like 'get_current_price' or 'get_batch_prices', which prevents a perfect score.

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 some usage context by mentioning data sources ('Source: clobTokenIds from list_active_markets or get_market_details') and an example, which implies when to use it. However, it lacks explicit guidance on when to choose this tool over alternatives (e.g., 'get_current_price' for real-time data or 'get_batch_prices' for multiple tokens), leaving room for ambiguity.

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