pricing

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, but the description adds meaningful behavioral context: it returns a machine-readable price list with specific credit conversion, free-tier size, and the wallet-native x402 rail. No contradiction with 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 two sentences, front-loaded with the core purpose, and every phrase earns its place—credit conversion, free-tier size, decision usage, and payment rail. No fluff or repetition.

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 no parameters and an output schema exists, the description covers the essential return content (prices, free tier, x402 rail) and the intended use-case timing. It is complete for an informational tool in this sibling context.

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?

There are zero parameters, so the description carries no burden for parameter semantics. The baseline of 4 applies, and the description adds context about the purpose (decision-making before calls) that complements the empty input schema.

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 provides a machine-readable price list, free-tier size, and payment rail, using specific verbs and resource types. It distinguishes itself from sibling verification/audit tools by focusing on pricing and payment-info lookup.

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 provides clear context: use it 'before it calls' to decide based on pricing and free tier, and to determine the x402 rail when free tier is exhausted. It does not explicitly mention alternatives or exclusions, but the context is sufficient for a simple informational tool.

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