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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the description adds value by detailing non-custodial settlement behavior and the specific report components. It goes beyond the structured hints to give the agent a fuller behavioral picture, including the fact that earnings settle to the withdrawal address on release.

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, information-dense sentence that leads with the primary purpose and then enumerates return items. It is efficient and every clause adds value, though it is slightly long and could be split for readability without losing content.

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 there are no parameters and an output schema exists, the description is complete: it explains what the tool does, what it returns, and adds a behavioral nuance (non-custodial settlement). An agent has everything needed to invoke it correctly.

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 takes zero parameters, so the schema is trivially covered and the description doesn't need to explain parameters. It instead focuses on what the tool returns, which is appropriate. Baseline of 4 applies given the absence of parameters.

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 specific verb ('Check') and resource ('earnings'), and enumerates the concrete items returned (lifetime USDC, pending amounts, claim-later rewards, payout balance, buyer spend, reputation). This clearly distinguishes it from sibling tools like data_preview or get_recommended_action by focusing on the user's own 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?

The description implies usage ('Check how much I have earned') but does not explicitly state when to use this tool versus alternatives, nor does it mention exclusions or scenarios where another tool would be preferred. The context is clear but lacks explicit routing guidance.

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