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

Annotations already establish this as read-only, idempotent and not open-world, so the bar is lower. The description still adds non-obvious behavioural context: the Pro-tier gating, the stale ~2019 data window, and fuzzy partial-name matching — all things the agent cannot derive from annotations or schema.

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?

Front-loads the purpose and return content, then a compact Args block. The parameter list is somewhat redundant in form, but since the schema has zero descriptions it earns its place rather than padding.

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?

An output schema exists, so return values need not be explained, and the description covers gating, data staleness, matching behaviour and parameter ranges. It stops just short of stating error/empty-result behaviour for unmatched names, which is the only real gap.

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 0% and no enums are declared, so the description carries the full burden — and it does: it documents case-insensitive partial matching for trainer_name, the three valid race_code values with 'gallops' as default, and the 14–365 day range for window. Without this text the parameters would be unusable.

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 ('Get') and resource ('track-by-track performance statistics for a trainer') and enumerates the return content: career runners, win rate, per-venue breakdown. The trainer focus separates it cleanly from the sibling get_jockey_stats.

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 '(Pro tier)' tag and the note that stats use a ~2019 data window imply context and eligibility, but the description never says when to prefer this over neighbours like get_runner_profile or search_runner, nor what to do when a trainer matches nothing.

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