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

No annotations are provided, so the description carries the burden. It discloses the returned fields (rank, score, solved, wrong, time), which is genuinely useful given there is no output schema, but it says nothing about authorization, defaults (e.g. which league when omitted), ordering, or result-size limits.

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?

A single dense sentence with the primary resource front-loaded and format details after a semicolon; no filler. It is arguably too terse, but nothing 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 no annotations and no output schema, the description does the minimum useful work: it names the return columns and the period grammar. It omits default behavior for league/period, ordering, and pagination, which an agent would need for a ranked-list 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 description coverage is only 25% (only 'format' is annotated), so the description must compensate. It does add the critical period syntax (day, week, YYYY-MM-DD, YYYY-Www) for an unannotated string parameter, and ties league to filtering, but it never explains the game enum values or league tiers, leaving a real gap.

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 and view: a game's leaderboard, filtered by league, with the returned columns enumerated. An agent can tell this is a read of ranked results, distinct from game_start/game_answer siblings. It does not, however, name any sibling it should not be confused with.

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?

Usage is implied by 'leaderboard' and the period-format hints, which condition how it is invoked. There is no explicit when-to-use/when-not guidance and no alternative tool is named among a large sibling set.

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