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

Beyond the readOnlyHint=true annotation, the description discloses tennis-only scope, the 2026 default season, optional ATP/WTA tour behavior, the 20-match qualification threshold, parallel-safety, and upstream cost. This adds substantial behavioral context beyond what annotations alone would convey.

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 definition is front-loaded and well-sectored, but the first sentence is repeated almost verbatim in the 'When to use' bullet, adding minor redundancy. Overall it remains appropriately sized and scannable.

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?

For a leaderboard tool with an output schema and 5 parameters, the description covers scope, defaults, routing, qualification criteria, and operational traits. Nothing critical is missing for an agent to select and invoke it correctly.

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 by explaining cross-parameter behavior: tour is optional and omitting it yields the combined board, division is a synonym for tour, and the 20-match qualification threshold affects results. It does not deeply explain the game parameter, but the enum already bounds it.

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 opens with a specific, unambiguous definition: 'Share of matches won after losing the first set per player, from real first-set rows joined to completed matches, ordered highest pct first.' This names the exact metric, source rows, and ordering, clearly distinguishing it from sibling leaderboard_* tools.

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 description explicitly provides 'When to use', 'Prefer over', and 'Do not use when' sections, naming concrete alternatives such as standings, rankings_movers, and player_form for different intents. This is exemplary routing guidance.

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