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

With no annotations, the description carries the full burden and does reasonably well: it discloses the payload contents (top markets by volume, blended live probabilities, resolution dates, per-market slugs) and the transport/cost (HTTP GET, $0.04 via x402). It omits update cadence, pagination, and error behavior, keeping it short of a 5.

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 the core purpose, then elaboration, then machine-readable metadata. Slightly redundant between 'All active US politics markets with live probabilities in one call' and 'One-call board of the most active US politics prediction markets,' but overall tight and well ordered.

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?

With no output schema and no annotations, the description must describe the return, and it does list the key fields (volume, blended probabilities, resolution dates, slugs). Missing limit/pagination semantics and freshness details leave minor gaps for a one-parameter board tool.

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?

The single parameter (limit) has 0% schema description coverage and is never mentioned in the description. 'Top markets by volume' faintly implies an ordered top-N cut, but the default, min, and max are left entirely to the schema, so the description adds no meaning beyond structured data.

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 (active US politics prediction markets) and what it returns (live probabilities, resolution dates, slugs) in one call. The 'politics-us' scope is explicit enough to separate it from the sibling probability_board_politics-world without opening either 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?

Usage is implied via 'the bulk read for agents tracking the state of US politics at a glance' and the mention of 'per-market slugs for drill-down,' which hints at a follow-up tool. However, no alternative is named and no when-not condition is given (e.g., use probability_board_delta for changes, probability_get for a single market).

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