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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds meaningful behavior beyond that: the pre-race vs post-race distinction ('after the race the winner, starting price'), the multi-language sentence variant, and a data-quality note ('Facts only').

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 sentence front-loads the core purpose and then lists content. It is information-rich with little waste, though the long semicolon-chained clauses make it slightly run-on.

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 carries the burden of describing returns and does so thoroughly (pre-race and post-race fields, formatting, languages). Only the usage/alternative-selection guidance 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 coverage is 100%, so the baseline is 3. The description adds value beyond the schema by clarifying that lang produces 'each statement also as a sentence', expanding on the schema's narrower 'language of team, league and country names' wording.

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 ('Ready briefing for one horse race') and then enumerates the exact content scope (field size, distance, going, form figures, strike rates, winner/SP). This is clearly distinguishable from siblings like get_race (raw race data) and get_runner_form (single runner).

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?

No statement of when to use this versus alternatives such as get_race, get_races or get_runner_form, and no prerequisites or exclusions. The content list implies a comprehensive-briefing use case, but the agent is left to infer that.

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