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

Annotations already mark the tool readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description goes beyond this by detailing the return contents (released escrows, claimed rewards, in-flight pending, unclaimed claim-later rewards, payout-address balance, buyer spend summary, reputation) and explaining settlement semantics: earnings settle non-custodially to the withdrawal address on release. This adds meaningful behavioral context without contradicting any annotation.

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, with the core purpose front-loaded in the first clause and every subsequent phrase adding specific useful detail. No filler, and the structure makes the read-only nature and settlement behavior easy to scan.

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 query with no output schema, the description is complete: it states what the tool does, what the returned information includes, that it is read-only, and how earnings settle. The sibling context is unrelated, and the annotations cover safety semantics, leaving no important information 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?

The tool has zero parameters, so there is no parameter documentation burden on the description. The schema already states that no arguments are needed and the owner is derived from the authenticated principal, and the description reinforces this implicitly. Baseline for 0 params is 4, and nothing here warrants a lower score.

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 exactly what is included: lifetime USDC earned, pending amounts, unclaimed rewards, payout balance, buyer spend summary, and reputation. This clearly distinguishes it from any sibling tool, none of which appear to overlap with earnings checking.

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 the natural use case: when a user wants to know what they have earned and what is pending. It also specifies that the owner is derived from the authenticated principal, so no arguments are needed. It does not explicitly name alternatives or exclusions, but no sibling tool covers earnings, so the lack of exclusionary guidance is not a significant gap.

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