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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false. The description adds meaningful behavioral context by stating earnings settle non-custodially to the withdrawal address and that the owner is derived from the authenticated principal. It reinforces the read-only nature without contradicting 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 dense but well-organized: it states the core purpose in the first sentence, then itemizes the returned categories, and ends with a relevant non-custodial settlement note. It is longer than minimal, but every sentence contributes useful information.

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?

With no output schema and no parameters, the description carries the burden of explaining what the agent will receive. It does so thoroughly by listing lifetime earned USDC, pending amounts, unclaimed claim-later rewards, payout-address balance, buyer spend summary, and first-agent reputation. Nothing essential is missing for a successful call.

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 and schema coverage is 100%, so the baseline is 4. The description adds value by clarifying that the context is the authenticated principal's earnings and specifying what the returned data represents, even though no parameters need explanation.

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 opens with a direct verb and resource ('Check how much I have earned and what is pending') and then enumerates the exact data categories returned, making the tool's purpose unmistakable. It clearly distinguishes itself as a read-only earnings overview tool among the sibling tools.

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 it clear this tool is for checking earnings and pending amounts, which is sufficient context for the typical caller. It does not explicitly name alternative tools or state when not to use it, but the zero-parameter design and specific output scope reduce ambiguity.

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