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

With no annotations, the description carries the disclosure burden and does so richly: free preview, first-3 limit, no LLM, every claim carries source and retrieval time, byte-reproducible canonical JSON. The only flaw is internal ambiguity—it first calls the report 'signed (Ed25519...)' and then says 'unsigned'—so the preview's signature status is unclear.

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 dense but front-loaded: it opens with purpose and preview status, then lists checks, output format, input formats, constraints, and routing in a logical order. Every sentence contributes, though the signed-format parenthetical adds some length.

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 3-parameter tool with nested objects and no output schema, the description covers what the report contains, input formats, limits, payment status, verification/no-LLM behavior, and sibling routing. It is incomplete only on the semantics of the options object, which is left undocumented.

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 67%, so the description adds some value by reinforcing that structured references or BibTeX are alternative inputs, which matches the 'exactly one of references / bibtex' constraint. However, it does not explain the two nested options, strict_authors and include_unpaywall, which are otherwise undocumented in the schema.

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 clear verb ('Verify a bibliography') and resource, enumerates the checks (exists, resolves, retracted, title/author/year match, fabrication risk), and differentiates from evidence_pack by noting it checks references you already have rather than finding papers.

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?

Explicitly tells the agent when to use this tool ('Use this to check references you already have') and when not to ('to find papers for a question or claim, use evidence_pack_preview / evidence_pack instead'). It also discloses the free-preview scope: first 3 references, unsigned, no payment.

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