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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds meaningful context beyond that: results are scoped to today's card and the payload is a per-track aggregation of races with named fields, which tells the agent the call is a snapshot rather than a historical query.

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?

Two sentences, front-loaded with the verb and resource, then the field inventory, then the prerequisite. The long field enumeration is dense but earns its place by telling the agent what data is available without opening the output schema. Slightly list-heavy but no filler.

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 one required parameter at full schema coverage, readOnly/openWorld annotations, and an output schema present, the description supplies everything needed: what is returned, the time scope, and where the input code comes from. Nothing an agent needs in order to call it correctly is missing.

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 description coverage is 100% and the single `code` parameter is already documented with the same example (LRL). The description's 'needs a track code from fanduel_racing_tracks' reinforces provenance but adds no format, case, or validity detail beyond the schema. Baseline 3 applies.

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 and resource ('Get one FanDuel Racing track') with explicit scope ('with all of its races today') and enumerates exactly what comes back: post time, minutes to post, status, surface, class, distance, purse, runner count. The mention of needing a code from fanduel_racing_tracks implicitly draws the line between this detail tool and the track-list sibling.

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 see a track's whole card' gives a concrete use case, and the prerequisite ('it needs a track code from fanduel_racing_tracks') tells the agent it must call the sibling first. No explicit when-not or alternative for viewing a single race (fanduel_racing_race), so it stops short of full routing guidance.

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