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

Annotations are absent, so the description carries the full burden and it handles it thoroughly: it discloses the Ed25519/RFC-8785 signed byte-reproducible JSON, no-LLM provenance, the $3.00 per-call payment, the unpaid isError response, the returned payment-settled fields, and the client-side spend-cap failure mode. This goes well beyond typical descriptions.

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 text is dense but earns every phrase: checks, signing format, input kinds, no-LLM guarantee, pricing, error behavior, and the spend-cap workaround are each actionable. Nothing is filler, and the most time-critical warning about the client default cap is placed where it can prevent a failed call.

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?

For a tool with no output schema, the description conveys nearly everything needed to call it correctly: the checks performed, input constraints, payment flow, failure modes, and the exact client configuration to change. The main completeness gaps are the undocumented options object and the unresolved 75-versus-200 references discrepancy, so it is very strong but not fully complete.

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 description only restates that input is structured references or BibTeX, which the schema already conveys (67% coverage). It does not explain the options object or the boolean options strict_authors and include_unpaywall, and it says "up to 75 references" while the schema's maxItems is 200, leaving an unexplained discrepancy that suppresses additional semantic value.

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 states a specific verb and resource: "Verify a bibliography" and enumerates concrete checks: existence, resolution, retraction, title/author/year match, and fabrication risk. The "large tier" plus paid/75-reference bound distinguishes it from the sibling citation_report family even without opening the schema.

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?

Provides clear context: input can be structured references or BibTeX, supports up to 75 references, and requires a paid x402 call, including a specific spend-cap warning that the client refuses to send otherwise. It does not explicitly name alternatives or explain when to choose this over citation_report_preview or citation_report, so it stops short of explicit when-not-to-use guidance.

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