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

With no annotations provided, the description must disclose behavioral traits. It only states 'no auth', which is useful but incomplete. It does not clarify whether the tool is read-only, makes network calls, or returns static or dynamic information, leaving agents with limited understanding of side effects or dependencies.

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 a single sentence, highly concise and to the point. It front-loads the essential purpose and adds a practical note about authentication. Every word earns its place, with no unnecessary 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 simplicity (zero parameters, no output schema, no annotations), the description is minimally acceptable but leaves gaps. It tells what the tool is about, but lacks specifics on what 'pricing' or 'setup info' entails or what the response will look like. For an agent to decide whether to use it, the description is adequate but not rich.

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 provides no additional detail to describe. The baseline for no parameters is 4, and the description does not need to compensate for missing parameter information. It adds no extra semantics but also does not need to.

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 that the tool provides x402 wallet pricing and setup information. It names a specific resource and scope, distinguishing it from sibling tools like estimate_cost or web_search. Although it lacks an explicit verb, 'info' effectively conveys the action of retrieving information.

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 gives no guidance on when to use this tool versus alternatives. The only additional detail is 'no auth', which is a prerequisite, not a usage context. There are no mentions of exclusions or scenarios where a different tool would be more appropriate.

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