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

Annotations already declare the read-only, idempotent, non-destructive nature. The description adds valuable context beyond annotations: the requirement of a free Messe Atlas account and the output fields (rank, name, value, slug) for typed calls. It could mention pagination or limits, but for a simple list tool this is solid.

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?

Three short sentences, front-loaded with the account requirement, then the two behavioral modes. No filler or redundancy; every sentence carries necessary information.

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 the low complexity (one optional parameter, no output schema) and annotations that already cover safety, the description is complete. It tells the agent about authentication, both call modes, and return fields, leaving nothing critical unspecified.

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 schema has 100% coverage and already documents the `kind` parameter, including its pattern and an example. The description adds meaning by explaining the effect of including vs omitting `kind`, which helps an agent invoke the tool correctly. Slight additional value beyond 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 describes what the tool returns in both modes: available leaderboard kinds when called without `kind`, and ranked rows when called with `kind`. The verb 'list' is implied by the name and the resource is unambiguous. It does not explicitly differentiate from sibling tools, though none overlap with leaderboards.

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?

It gives a clear two-step usage flow: call without `kind` to discover available kinds, then pass a `kind` to retrieve rows. This is strong contextual guidance. However, it does not state when not to use it or name alternatives, keeping it from a 5.

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