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

With no annotations the description carries the full burden, and it does disclose real behavior: a GET (read) endpoint, results in date order, blended probabilities, and critically the $0.01 x402 payment requirement — context an agent needs before invoking. It stops short of documenting the response shape or any pagination/rate-limit behavior.

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?

Front-loaded and mostly efficient, but the first two sentences are near-duplicates ('Upcoming world politics event resolutions' / 'Upcoming world politics market resolutions...'), which is minor waste. The endpoint/price/docs footer is compact and useful.

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?

No output schema or annotations exist, so the description must carry returns, and it conveys shape (date-ordered rows with blended probabilities) and a reference point ('same shape as /v1/calendar'). It is nearly complete for invocation, with the missing parameter semantics being the main hole.

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 0% for two parameters, so the description must compensate and does not. 'days' is never explained as a forward window (despite min/max 1–90), and the 'category' enum is left unaddressed even though it sits oddly against a tool described as pre-filtered to world politics.

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?

States a specific resource (upcoming world politics market resolutions) plus scope ('in date order with current blended probabilities') and explicitly differentiates from the base calendar by being 'pre-filtered to world politics markets.' An agent can distinguish it from probability_calendar, probability_board_politics-world, and probability_movers_politics-world without opening any schema.

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 note 'Same shape as /v1/calendar, pre-filtered to world politics markets' implies you should choose this when you want only world politics, but there is no explicit when-to-use / when-not or named alternative beyond that. Usage is inferable rather than stated.

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