lichess_leaderboard

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

Annotations already declare readOnlyHint, openWorldHint, and idempotentHint, establishing a safe read operation. The description adds valuable context: the exact return format ({users:[...]}) and explicitly states 'Auth: none needed.' This goes beyond the annotations without contradicting them.

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 compact and well-structured: a one-line purpose, a return format snippet, a concrete example, and an auth note. Every sentence delivers useful information with no fluff, making it easy to scan and understand.

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 simple 2-parameter tool with complete schema descriptions and strong annotations, the description is fully adequate. It includes the return shape, an example, and auth requirements, so an agent has all necessary information to call it correctly without needing an output schema.

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?

Input schema covers 100% of parameters with descriptions and defaults for both 'perf' and 'count', so the description doesn't need to repeat them. The example re-illustrates the parameters but doesn't add new semantic meaning beyond 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 clearly states the tool returns top-rated players for a specific time control or variant, using a specific verb ('Top-rated players') and the resource (lichess leaderboard). It distinguishes from the sibling 'lichess_leaderboards_all' by focusing on a single perf, though it doesn't explicitly name the alternative.

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 usage through the example 'Top 10 blitz players' with count and perf, indicating how to request a specific leaderboard. However, it doesn't provide explicit guidance on when to use this tool versus siblings like lichess_leaderboards_all, nor when not to use it.

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