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

With no annotations, the description carries the safety burden, and it does well: 'Check' implies a read-only operation, and it discloses the return fields (balance, can_pay, shortfall). It also points to a sample endpoint. It doesn't discuss errors or exact response shapes, but the core behavior is transparent.

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?

Three tightly packed sentences with no filler. The core action is front-loaded, the return fields are listed, and the sample endpoint is a useful addition that earns its place.

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 two-parameter check tool with no output schema, the description adequately covers inputs, purpose, output fields, and a discovery hint. It could mention exact value formats or error cases, but nothing critical is missing for an agent to invoke it correctly.

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 coverage is 0%, so the description must add meaning. It clarifies that amount is an x402 amount denominated in USDC and notes the $0.001 default. Address is only implicitly described as a Base wallet address, which is inferable but not explicit. The description partially compensates for the missing schema descriptions.

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'), a clear resource ('Base wallet'), and a precise condition ('holds enough USDC to pay an x402 amount'). This fully distinguishes it from the unrelated 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?

It explicitly frames the tool as 'the checklist agents run before spending,' giving clear situational context. It does not name any alternative tools or exclusions, but the sibling set is diverse enough that the intended use is obvious.

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