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

Annotations already establish read-only, idempotent, non-destructive behavior, and the description adds real value beyond them: it explicitly disclaims signing, spending, and settlement proving, and discloses that the returned hints may be stale relative to fresh resource requirements. No auth or rate-limit context, but the scope limitations are the right disclosure for this tool.

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 dense sentences, front-loaded with what is read and returned, then the override caveat. No filler, though the x402/Base/USDC jargon load makes it slightly heavy for a zero-parameter read.

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?

An output schema exists so return values need no prose explanation, and the description still covers the two things the schema cannot: the staleness caveat and the explicit non-signing/non-settlement boundary. Complete for a zero-param read tool, with only cross-tool routing left implicit.

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 takes zero parameters, so the baseline is 4 per the rubric. The description correctly adds no parameter guidance and there are no parameters to clarify.

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?

States a specific verb (Read) and resource (SML x402 v2 Base/USDC configuration and receiver) and clarifies what it returns (configuration plus a read-only policy). It doesn't name any sibling explicitly, but the phrase 'before selecting a paid route' positions it against check_payment/list_paid_apis in the workflow.

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?

Gives clear usage timing ('before selecting a paid route') and an important exclusion rule ('Fresh resource requirements override these hints'), which tells the agent when not to trust this output. It stops short of naming which sibling to call instead for signing, spending, or settlement proof.

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