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

Annotations already mark the operation as read-only, idempotent, and non-destructive. The description adds useful context about response rows, the read-only nature of score-protection settings, and the semantic meaning of `id`, without contradicting the 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 description is short and dense, front-loading the purpose and packing field semantics into one sentence. The opening fragment 'The leaderboards of a game' is slightly awkward but not wasteful.

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 single-parameter, read-only list tool, the description covers the output fields and the cross-tool id relationship, and the schema covers the input. It does not explicitly state the return container or pagination, but the 'rows' wording implies a list and nothing critical is 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?

The only parameter, applicationId, is fully described in the schema as 'Application (game) id, as returned by list_applications.' The description does not elaborate on this parameter; its `id` explanation refers to a row field, not the input. Baseline 3 applies because schema coverage is 100%.

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 title 'List leaderboards' supplies a specific verb, and the description defines the resource as 'the leaderboards of a game.' It also clarifies that `id` is the SDK tag and the identifier consumed by update_leaderboard, which distinguishes this read tool from its update sibling.

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 implies a workflow—listing leaderboards gives you the `id` needed for update_leaderboard—but it never explicitly states when to choose this tool over create_leaderboard or update_leaderboard. There are no prerequisites or exclusions, only minimal implied guidance.

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