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

With no annotations, the description carries the burden and does well: it discloses the stable-URL behavior, auto-resolution/roll-forward semantics, and that the payload adds current_slug and rolls_to_next_at to the standard probability shape. It lacks detail on latency/rate limits but covers the meaningful behavioral traits.

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, then mechanics, then response shape, then a dense HTTP/price/docs footer. Slightly repetitive in restating the question verbatim twice, which costs it the top mark.

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 and no params, so the description must orient the caller and does: it names the standard probability shape plus the two added fields. Documentation link and price are supplied, making it operationally complete.

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?

Zero parameters, so the baseline is 4. There are no inputs to document and the description correctly indicates no argument is required.

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 (a live probability for the US-China tariff question) with a clear scope qualifier ('this quarter'). The evergreen framing distinguishes it from the board/calendar/search siblings that surface specific market instances.

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?

Explains the evergreen mechanism and why you'd use it: auto-resolves to the current instance and rolls forward so the answer always concerns the next occurrence. That implies when it's preferable to a point-in-time lookup, but no explicit alternative is named.

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