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

With no annotations, the description carries the full burden. It does add genuinely useful context — the GET endpoint, the $0.01 x402 payment requirement, and the 'same shape as /v1/calendar' return-shape hint — but omits auth details beyond x402, rate limits, and what a 'blended probability' actually aggregates. Pricing disclosure is the strongest behavioral contribution.

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 with purpose in the first sentence, and the bracketed HTTP/pricing/docs metadata is compact and skimmable. Slight redundancy between 'Upcoming soccer event resolutions' and the following sentence restating the same idea, but overall tight.

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 simple list tool with no output schema, the description conveys enough to call it, but with 0% param coverage and no explanation of the return payload beyond a cross-reference to another endpoint, an agent still lacks the details needed to interpret 'days' or the blended-probability field structure. Adequate but with clear gaps.

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%, so both parameters (days, category) are undocumented anywhere. The description mentions date ordering and soccer filtering but never explains what 'days' controls, its 1–90 range, or that 'category' is an enum that is arguably redundant on a pre-filtered soccer tool. The description does not compensate for the coverage gap.

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 (soccer market resolutions) with clear scope (upcoming, date order, current blended probabilities) and explicitly positions itself as the soccer pre-filter of /v1/calendar. An agent can distinguish it from the generic probability_calendar and the other sports variants without opening a 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?

It implies usage via 'the forward calendar of soccer events an agent can position around' and notes it is pre-filtered to soccer markets, which routes away from the generic calendar. However, it never names the sibling alternatives (probability_board_sports-soccer, probability_movers_sports-soccer, probability_search) or states when this forward-looking view is preferable to a board or movers view.

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