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

Annotations already declare read-only, idempotent, non-destructive behavior, so the description need not repeat safety details. It adds useful behavioral context beyond annotations by disclosing the 3-credit cost and the league/tour handling for ATP versus WTA, including the shared-endpoint quirk for WTA.

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 description is front-loaded with the core use case and packs in relevant metric details, cost, and parameter quirks without extraneous prose. It is somewhat dense and the ATP/league wording could be cleaner, but every part broadly serves the agent.

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?

Given that an output schema exists and annotations cover safety behavior, the description is complete for invocation: it describes the returned surface metrics, the season/career scope, by_season behavior, league handling, and cost. No critical invocation detail appears 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 baseline is 3, but the description adds meaningful semantics for season, by_season, and league: it explains that season defaults to the whole career, by_season splits each surface by year, and WTA access on the shared endpoint requires league="wta". The ATP/WTA note is slightly confusing against the schema enum tennis/wta, but still adds value.

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?

The description clearly states the resource: a player's record split by surface, including specific metrics returned. It is specific enough to distinguish this from general player stats or ratings, though it does not explicitly name sibling tools or explain when to use those alternatives.

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?

It gives clear context for using the tool: for a player's surface-level record, for one season or the whole career, and with by_season to split each surface by year. It does not provide explicit when-not-to-use guidance or name alternatives like get_player_stats or get_ratings.

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