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

The annotations already convey read-only, idempotent, open-world, and non-destructive behavior. The description reinforces 'Read-only' but also adds meaningful non-obvious context: earnings settle non-custodially to the withdrawal address on release. This goes beyond what the annotations state and is valuable for the agent.

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, no wasted words. The first sentence leads with the core purpose and then lists the return contents in a compact, scannable way. The second sentence adds an important behavioral caveat about non-custodial settlement without padding.

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 read-only tool with an output schema, the description is fully complete. It covers the tool's scope, what data it returns, its read-only nature, and a notable settlement behavior. There are no missing prerequisites, side effects, or usage constraints an agent would need.

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, so the baseline is 4. The input schema already explains that no arguments are needed and the owner is derived from the authenticated principal. The description adds nothing about parameters, but none is needed.

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 clear verb ('Check') and resource ('earnings') and enumerates exactly what it returns: lifetime USDC, pending amounts, unclaimed rewards, payout balance, buyer spend, and reputation. This level of scope specificity distinguishes it from all sibling tools without needing to inspect schemas.

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 makes the usage context obvious: it is for answering questions about earnings as a seller, including pending and unclaimed amounts. It does not explicitly name alternatives or exclusions, but with zero parameters and a unique earnings focus, the intended trigger is clear enough.

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