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

With no annotations, the description carries the full burden and does well: it discloses auto-resolution behavior, roll-forward on resolution, the additional response fields (current_slug, rolls_to_next_at), and the access/cost model (HTTP GET, $0.02 via x402). It does not describe latency, rate limits, or failure modes.

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 question and probability, then the evergreen mechanics, then response additions, then transport/cost metadata. Tight overall, though the bracketed HTTP/price/docs boilerplate is somewhat dense.

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?

There is no output schema, but the description compensates by naming the extra response fields and the standard probability shape. Combined with the auto-roll explanation, an agent has enough to call and interpret this correctly; only the base response shape is left to outside knowledge.

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 tool takes zero parameters, so the baseline is 4; there is nothing for the description to clarify beyond confirming the question is fixed by the slug itself.

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 states a specific resource (live probability for a named recurring question) and a distinguishing behavioral trait versus the non-evergreen siblings: it is a stable URL that auto-resolves to the current market instance. It does not explicitly contrast itself with probability_get or probability_search, so an agent must infer the boundary.

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 rather than stated: the 'evergreen / recurring question / rolls forward on resolution' framing tells an agent this is for tracking the same question over time, but there is no explicit when-to-use-this-instead-of-X guidance against the many sibling probability tools.

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