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 the evergreen auto-resolution behavior, that it rolls to the next instance on resolution, the added response fields (current_slug, rolls_to_next_at), and the payment requirement ($0.02 via x402). Auth/rate-limit behavior beyond the price is not covered.

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 question and the evergreen semantics, and the HTTP/price/docs footer is compact. The question text is restated twice (once as the headline, once after 'recurring question'), which is mild redundancy.

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, the description steps in by noting the response follows the 'standard probability shape' plus current_slug and rolls_to_next_at, so an agent knows roughly what comes back. Payment and endpoint details round it out; only auth/rate-limit specifics are absent.

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 per the baseline rule a 4 is appropriate. The description correctly adds no parameter detail because there is nothing to parameterize.

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 verb+resource: a live probability on whether the next US GDP print shows growth, with the recurring/evergreen framing made explicit. The subject matter is specific enough to separate it from data tools like econ_series_gdp-growth, but it never explicitly contrasts itself with the other probability_evergreen_* tools.

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?

Gives solid context that the answer is 'always about the next occurrence' and that the URL rolls forward, which implies when the tool is appropriate. However, there is no explicit when-to-use/when-not guidance and no named alternative for a fixed-date or historical GDP question.

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