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

Annotations already declare readOnlyHint and openWorldHint, so the description's value-add is the commercial model: $0.002 USDC per successful call via x402 across Base/Solana/Arc, with failed calls not charged. That is genuinely useful pre-call context an agent cannot infer from schema or annotations. It stops short of noting rate limits or result-ordering/relevance behavior.

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?

Three tight sentences: capability first, limitation second, cost third. Every sentence carries information, with no filler. The field list is slightly dense but front-loads what matters most.

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 structure need not be explained, and the pricing/auth model is disclosed. The main missing piece is sibling routing against search_crossref_academic_paper; otherwise an agent has what it needs to call this 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% for both parameters (q with a 1-200 char bound, rows with a 1-20 bound and default 5), so the schema does the heavy lifting. The description adds nothing about query syntax, field scoping, or sorting, so baseline 3 is warranted.

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+resource (Crossref works search) and enumerates the record fields returned (DOI, title, type, container, year, authors, link), so an agent knows exactly what comes back. However, it never distinguishes itself from the near-identical sibling search_crossref_academic_paper, which is a real ambiguity in this sibling set.

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?

Usage is only implied: 'Metadata only; abstracts are not always present' warns what not to rely on, and 'no key' signals low-friction access. There is no explicit when-to-use or when-to-prefer-an-alternative statement, which matters given the overlapping Crossref sibling and the many other scholarly search tools (PubMed, DataCite, Europe PMC, Unpaywall).

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