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

Annotations already declare this is a read-only, idempotent, non-destructive, closed-world tool. The description adds meaningful behavior beyond annotations by explaining that counting stats are summed and rate stats averaged, plus the 5-credit cost.

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, followed by compact aggregation behavior, filters, and cost. The stat examples are long but directly useful for selecting the required stat parameter, and no sentence is wasted.

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 an output schema present, rich annotations, and full schema description coverage, the description supplies the remaining decision-critical context: ranking purpose, aggregation semantics, filter scope, and credit cost. Nothing essential for correct invocation 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 the schema already documents each parameter. The description adds useful semantics for the stat parameter by explaining the aggregation rule: counting stats are summed and rate stats are averaged.

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 states a specific verb and resource: rank players on weekly stats over a season, with example stat columns. It clearly distinguishes leaderboard-style ranking from raw stat retrieval, though it does not explicitly name a sibling tool such as get_player_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 opening phrase 'Use to rank players...' gives clear when-to-use guidance, and the description mentions supported filters and the 5-credit cost. It does not specify when not to use this tool or name alternatives, so it stops short of full alternative routing.

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