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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and non-destructive behavior. The description adds useful context beyond those annotations by specifying that the result is ledger-backed and only actual settled earnings, and that estimates are explicitly excluded. 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 a single concise, front-loaded sentence. Every word adds value, and the key distinction between actuals and estimates is stated immediately.

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?

Annotations cover the safety profile, and the tool is a simple read-only check. However, the description does not state the return format or clarify how account_handle and account_token should be sourced, and there is no output schema to fill that gap.

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?

Schema description coverage is 0%, and the description does not explain account_handle or account_token at all. Since there is no complementary documentation in the schema, the description fails to compensate, leaving parameter semantics completely unexplained.

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 a specific operation ('check') and a specific resource ('ledger-backed actual settled earnings'). It also draws a meaningful boundary by saying 'estimates are not earnings', which helps distinguish this from estimate-oriented tools. It does not explicitly name sibling tools, so it falls just short of a 5.

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 when to use the tool: when checking actual settled earnings rather than estimates. However, it does not explicitly mention any alternative tool or provide clear when-not-to-use / use-this-instead guidance, leaving the usage context mostly inferred.

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