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

With no annotations, the description carries the burden of behavioral disclosure. It does disclose the cost ($0.01 via x402), the live real-money nature, the data source, and the output scope. However, it does not explain what happens on payment failure, whether the call can return empty results for unknown keywords, or any rate limits or error conditions, which matters for a paid tool.

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 compact, information-dense, and front-loaded with the most important facts: cost, payment method, data source, and output fields. Every sentence contributes: the first defines the tool, the second gives search examples, and the third states target use cases and the value proposition. No wasted words.

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?

The description is reasonably complete for a read-only data-fetching tool with no required parameters and no output schema. It names the key return fields (implied probabilities, price moves, dollar volume, liquidity) and the search capability. It could be more complete by discussing x402 payment mechanics and empty-result behavior, but the core calling context is well covered.

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 baseline is 3. The description adds useful keyword examples and clarifies that results are the top markets by 24h volume, but it does not add substantial meaning beyond the schema for the top, sort, or x_payment parameters. It provides enough context without needing to compensate heavily.

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 names a specific resource (Polymarket prediction-market odds) and a specific verb/action (fetch live odds, top markets by 24h volume) along with the output fields. It clearly differentiates itself from sibling market tools like crypto_prices or market_overview by focusing on prediction markets and implied probabilities.

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 explicitly states the tool is for trading, forecasting, news, and event-resolution agents, which gives clear context on when to use it. It does not explicitly name alternatives or exclusion criteria, but the mention of 'One call instead of integrating the exchange API' helps an agent recognize it as a lightweight alternative to direct exchange integration.

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