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

Annotations already supply readOnlyHint, idempotentHint, and openWorldHint. The description adds meaningful context beyond those: earnings settle non-custodially, 'earned' is defined as released escrows plus claimed rewards, and unclaimed claim-later rewards are enumerated. No contradiction with annotations.

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 three sentences: a crisp overview, a detailed return-value list, and a short behavioral note. Every sentence earns its place, though the return-value list is somewhat dense and could be structured more cleanly.

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-argument, read-only query tool with rich annotations and no output schema, the description fully specifies the return contents, confirms read-only behavior, and explains the settlement model. Nothing an agent needs to decide whether to call this tool is missing.

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?

With zero parameters and schema description coverage at 100%, the schema fully documents the empty input. The description adds no parameter-level detail, but none is needed; the baseline of 4 is appropriate for a no-parameter tool.

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 uses a specific verb ('Check') and resource ('earnings'), and enumerates exactly what is covered: lifetime USDC, pending amounts, claim-later rewards, payout balance, buyer spend, reputation. However, it does not explicitly distinguish itself from any sibling tool, so it stops short of a perfect score.

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?

Usage is implied by the name and phrasing ('Check how much I have earned'), and the read-only nature is clear. There is no explicit guidance about when to prefer this tool over alternatives or what situations it is not for.

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