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

With no annotations, the description carries the full burden of behavioral disclosure. It does disclose that the tool returns totals net of fees, fill rate, and recent payouts, which implies a read-only query. However, it does not explicitly state that it is read-only, nor does it mention any side effects, caching, or data freshness. The disclosure is minimal but not misleading.

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 a single, concise sentence that front-loads the key information: what the market has actually paid, followed by specific components. There is no filler or redundancy, and every word contributes to the meaning.

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 zero-parameter tool with no output schema, the description is reasonably complete. It explains the core content (totals, fill rate, recent payouts) and implies a query action. It could benefit from noting that it is a read-only operation or specifying a time range, but given the simplicity, the description covers the essential context.

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 tool has zero parameters, and the input schema is empty. The description adds value by describing the nature of the returned data, but there are no parameter semantics to clarify. Since there are no parameters, a baseline of 4 is appropriate; the description does not need to compensate for missing schema details.

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 what the tool returns: actual paid totals net of fees, fill rate, and recent payouts. It specifies a resource (market earnings) and is informative, though it lacks an explicit verb and does not name sibling tools to differentiate from. It is more specific than generic terms like 'earnings'.

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?

No guidance is given on when to use this tool versus alternatives like hub_economy or hub_stats. The description implies it is for checking actual payments, but there are no explicit conditions, exclusions, or mentions of other tools. An agent must infer the appropriate context.

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