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

Annotations already declare it as read-only, idempotent, and non-destructive. The description adds behavioral specifics beyond annotations: the ranking is based on profit from sells, requires a minimum of three sells, and operates on pretend ETH with real fills. This clarifies the exact data and rules the agent can expect.

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 two sentences, information-dense, with no redundant wording. The core purpose and rules are front-loaded, making it easy for an agent to quickly grasp the tool's behavior.

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 listing tool, the description covers purpose, filtering criteria, and ranking logic. It does not describe the output format, but given the simplicity and the lack of an output schema, this is not a critical gap. The openWorldHint suggests the board may vary over time, which is implied by 'this week'.

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 'who' is fully described in the schema with enum values and a default (Everyone when left out). Schema coverage is 100%, and the description does not add additional semantic meaning beyond what the schema provides, so the baseline score of 3 applies.

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's function: it lists a practice league board ranking participants by profit from selling pretend ETH, with explicit criteria (only sells count, three or more sells). This distinguishes it from sibling tools like 'winners' or 'smart_money' by focusing on practice and specific rules.

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 provides explicit conditions for listing (only sells count, three or more sells), which informs when this tool is relevant. It doesn't explicitly name alternatives, but the context is specific enough that an agent can infer when to use it, and the openWorldHint suggests it may reflect changing data.

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