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

No annotations are provided, so the description carries full burden. It discloses meaningful behavior: the URL is stable/evergreen, it auto-resolves to the current market instance, rolls forward on resolution, and the response adds current_slug and rolls_to_next_at fields beyond the standard probability shape. It does not state auth/rate-limit behavior, but the HTTP/x402 pricing line implies the x402 payment requirement.

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 is stated twice (once in the opening line, once after the colon), and the description ends with an HTTP/docs URL block whose value is marginal for tool selection. The core facts are front-loaded and clear, but the duplication costs efficiency.

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?

For a zero-parameter evergreen single-question tool with no annotations and no output schema, the description covers purpose, evergreen/roll-forward mechanics, and the extra response fields. The main omissions are explicit auth/payment and rate-limit notes, though the x402/pricing tag gives a hint.

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 baseline is 4. The description correctly notes the response shape is the standard probability shape plus two extra fields, but since there's no output schema and no params, there's little schema semantics to supplement.

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?

Names a specific recurring question verbatim and states the resource is a live probability for it. The 'next FOMC dot plot shift' scope is unmistakable, and it's distinguishable from siblings like probability_evergreen_fed-next-meeting-cut which cover different Fed questions.

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 establishes context (stable URL for a recurring question that auto-resolves and rolls forward), which implies when to use it: when you want the current instance of this specific Fed question. But it does not explicitly compare against the broader probability_board_fed or probability_calendar_fed siblings, so the agent must infer that this is a single-question endpoint versus a board of many.

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