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

Annotations already cover read-only/open-world/non-destructive behavior; the description adds meaningful extras beyond them: that only players contesting at least 3 finals qualify, that data comes from real completed finals rows, that it is parallel-safe, and that upstream cost is 1. No contradiction with annotations.

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 key metric is front-loaded, and the bulleted When/Prefer/Do-not-use structure is easy to parse. However, the first bullet under 'When to use' repeats almost verbatim the opening sentence, adding minor redundancy in an otherwise efficient description.

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 schema coverage, output schema, and annotations, the description is complete enough for effective selection and invocation: it covers qualifying threshold, optional tour behavior, season default, ordering, parallel-safety, and routing. There is no missing information that would cause an agent to call this tool incorrectly.

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%, so the baseline is 3 even without extra parameter detail in the description. The description restates a few defaults (season 2026, optional tour, omitted for combined board) that are already present in the schema, but it does not add meaningfully beyond the schema for parameter usage.

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 opening sentence names a specific resource ('finals-record leaderboard'), a specific metric ('share of finals won per player'), a data scope ('real completed finals rows'), and an ordering ('highest pct first'). This clearly distinguishes it from sibling leaderboard_* tools that focus on aces, tiebreak win percentage, or break conversion.

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 states when to use ('share of finals won... clutch/serve-efficiency leader queries'), when to prefer a different tool ('prefer over call_api'), and provides a 'Do not use when' section mapping concrete alternatives such as standings, rankings_movers, and player_form. This is unambiguous routing guidance.

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