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 context beyond these: 'earnings settle non-custodially to your withdrawal address on release,' which explains the settlement behavior. It does not contradict the annotations; it enriches them.

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, front-loaded with the core purpose, and then enumerates the returned data items. It is somewhat dense but each element serves a purpose. No filler or redundant phrasing beyond the minor repetition of 'Read-only' which is already in annotations.

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 the tool has an output schema (not shown but indicated), the description does not need to detail return structure. It lists the major categories of returned data and the settlement note. For a read-only earnings query, this is sufficient. Could mention potential delay in settlement or edge cases, but not critical.

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 the schema fully covers parameter semantics by virtue of having none. The description confirms the owner is derived from the authenticated principal, which is additional clarity. With 0 params, a baseline of 4 is appropriate.

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 the tool's purpose: 'Check how much I have earned and what is pending.' It specifies the exact resource (earnings) and enumerates the returned components (lifetime USDC, pending amounts, unclaimed rewards, etc.). No sibling tool covers earnings, so it is unambiguously distinct.

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 implicitly defines when to use it—whenever the user asks about earnings or pending amounts. It does not explicitly name alternatives or exclusions, but given the sibling list contains no earnings-related tools, the intended usage is clear. The 'Read-only' note further clarifies it is a safe query operation.

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