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

With no annotations provided, the description carries the burden and does so well: it explains the auto-resolve/roll-forward behavior, notes the extra response fields, and discloses cost ($0.02 via x402) and endpoint. It stops short of auth/permission notes, but discloses considerably more than basic annotations would.

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?

The question 'Will the next CPI print come in above consensus?' is stated twice in the first two sentences, which is redundant and wastes space. Otherwise the structure is reasonable, front-loading the purpose before the trailing HTTP/cost/docs bracket.

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 must convey the return value, and it does partially by saying the response adds current_slug and rolls_to_next_at to the standard probability shape. Combined with the evergreen/roll-forward explanation, this covers what an agent needs to call and interpret the 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?

Zero parameters, so there are no input semantics to clarify; per the baseline this warrants a 4. The mention of current_slug and rolls_to_next_at concerns response shape rather than inputs.

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 (live probability for a recurring question) and names the exact question. An agent can immediately distinguish this from its many siblings (probability_get, probability_board_*, other probability_evergreen_* tools) because the question is spelled out.

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?

The description gives clear context for applicability: it is a stable evergreen URL for a recurring question that auto-resolves and rolls forward. This tells the agent when the tool is appropriate, though it does not explicitly name alternatives or exclusions (e.g., when to prefer probability_get or a board tool).

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