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

Beyond the readOnlyHint/openWorldHint annotations, it discloses state-dependent behavior ('once official, the finish order and payoffs') and that extra data is only returned when 'include' groups are requested. It does not mention missing-race errors or data latency, but the annotations already cover the safety profile.

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?

A single dense paragraph that front-loads the core payload and follows with the optional-parameter guidance and the requirement sentence. It is long but every clause adds content; slightly splitting the include guidance would improve scannability.

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 an output schema available, the description needn't detail return shapes, and it still conveys coverage of data, optional enrichment, and where to obtain required IDs. Only the upcoming-vs-historical boundary relative to fanduel_racing_past_race is left implicit.

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?

Schema coverage is 100%, so the baseline is 3; the description earns more by explaining what each include group buys ('handicapping... favorites rank', 'Timeform comments, tissue price, flags, finisher timing', 'per-entry pool pairings') and by pointing to fanduel_racing_tracks/races for the required IDs.

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?

Opens with a specific verb and resource ('Get one FanDuel Racing race in full') and enumerates the payload (entries, odds, price history, runner details, pools, payouts, will-pays, results). This clearly separates it from fanduel_racing_races (listing) and fanduel_racing_past_race (historical).

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?

'Use it to analyze a race' states the intent, and the description names the sibling (fanduel_racing_races) as the source of the required track/number. No explicit when-not guidance (e.g. upcoming vs. already-run race, or when to prefer fanduel_racing_past_race instead), which keeps it below a 5.

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