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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds important behavior beyond the annotations: the tool is paid at $0.002 USDC per successful call via x402 on Base, Solana, or Arc, and failed calls are not charged. That is exactly the kind of cost and payment-context disclosure an agent needs before invoking a paid external search.

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 compact and front-loads the core resource and return fields before describing filters, subject-less behavior, and pricing. It is dense but every clause contributes useful information. A slightly more structured presentation would improve readability without changing the content.

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 output schema and annotations, the description is complete enough to call the tool correctly. It covers the main return fields, filter behavior, subject-less listing mode, and the paid-call model, while the schema handles parameter details.

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 year, limit, country, subject, and university with examples and defaults. The description reinforces the subject examples and the omit-subject behavior, but adds little parameter meaning beyond what the schema provides.

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 identifies the resource as ShanghaiRanking GRAS and states that it returns ranked universities for a subject and year, including rank/band, scores, country, and institution URL. It also explains the subject-less listing behavior. It does not explicitly differentiate itself from nearby siblings such as search_shanghai_arwu_rankings or search_university_rankings_mega_pack, so sibling discrimination relies on the user already knowing GRAS vs ARWU.

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 gives clear usage context: provide a subject and year to get rankings, filter by country or university, or omit the subject to list available subjects and codes. This is actionable guidance. It stops short of naming alternatives or stating when another university-ranking 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.