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

With no annotations, the description carries the full burden and does so well: it discloses the price ($0.25 USDC on base via x402), that no account/API key/invoice is needed, the two-step payment handshake, and the deliberate exclusion of unprobed services. It does not cover failure modes (e.g., what happens with an invalid or expired payment) or rate limits.

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?

Front-loads the purpose, then price, then the call mechanics, then the paging and the absence caveat. Every sentence carries distinct information (cost, auth model, protocol flow, output ordering, exclusion rule) and nothing is filler.

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?

There is no output schema, so the description must describe the return: a ranked, 0-100 scored table ordered best-first with category tags, paginated. Combined with the payment flow and the unprobed-service caveat, an agent has everything needed to call and interpret this tool 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 description coverage is 100% and the schema already documents limit/offset ranges and defaults plus the payment omit/supply behavior. The description adds only the phrase "Page with limit and offset," which restates what the schema provides, so the baseline 3 applies.

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 resource and scope: "the full ranked table of every scored service," ordered best-first, scored out of 100. This implicitly separates it from the narrower sibling get_top_ten, but it never names that sibling or any other, so the differentiation is inferred rather than stated.

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 explicit operational sequencing: "Call without `payment` to receive the exact payment requirements, then call again with `payment` to be served." It also states a when-not condition (services never probed are absent, not ranked last) and specifies paging via limit/offset.

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