Create a Game Center leaderboard

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

With no annotations provided, the description carries the full transparency burden. It usefully discloses a nontrivial side effect: the call also creates the initial leaderboard version required by the API and returns that version's ID. It does not mention authorization or reversibility, but the most surprising behavioral trait is clearly surfaced.

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 sentences with no filler. The primary action is front-loaded, and the second sentence adds the essential return-value detail and workflow direction without redundancy.

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 that there is no output schema, the description's explicit mention of the returned version ID is valuable for an agent chaining into create_game_center_leaderboard_localization. It covers the key side effect and follow-up step. It stops short of describing error conditions or permission requirements, but it gives enough to invoke the tool correctly in the intended workflow.

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 89%, which exceeds the high-coverage baseline, so the schema already explains the parameters, enums, and required fields. The description adds no parameter-level detail, which is acceptable because there is little left to clarify beyond what the schema provides.

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: 'Create a new Game Center leaderboard.' It also differentiates this from the sibling localization tool by mentioning that it creates the initial leaderboard version and returns its ID, so the agent can distinguish where one workflow ends and the next begins.

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 context is implied rather than explicit: the description says the returned version ID lets you immediately add localizations with create_game_center_leaderboard_localization, which suggests a follow-up workflow. However, it does not explicitly state when to use this tool versus alternatives, nor does it state exclusions or prerequisites beyond what the schema already captures.

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