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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds two things the annotations cannot: a 5-credit cost and the default 10-match floor for per-90 ranking, both material to invocation and result set size.

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?

Two compact sentences front-load the use case, then the cost. Nothing is repeated and no filler is present.

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, return values need no explanation; the description covers stat scope, per-90 behavior, defaults and cost. It does not mention result ordering (implicitly descending) or a default for limit across all five optional parameters, which is a minor residual gap for a 6-parameter tool.

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 83% (high), so baseline is 3; the description exceeds it by disclosing that min_games defaults to 10 for per90 mode, a default the schema does not state. The stat enum and per90 toggle are only restated, and limit/league/season are left to the schema.

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 resource (a season's statistical leaders) and enumerates the exact stat categories covered, including the totals vs per-90 mode. It does not name a differentiating sibling (get_standings, get_team_stats) but its scope is nonetheless unmistakable from the stat enumeration.

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?

"Use for a season's leaders in..." gives a clear selection context, and the parenthetical explains the per90 variant including its default minimum-games threshold. No when-not-to-use case or named alternative is given, which keeps it out of the 5 tier.

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