paper

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

No annotations are provided, so the description carries the full burden, and it does disclose error behavior ('Fails with a clear message if the key is unknown') plus which data leaves the machine and to whom. It omits rate limits and any explicit read-only statement, but 'look up' plus the privacy section make the safety profile clear enough.

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?

Purpose, key format, return shape and failure mode are front-loaded into one dense sentence, which is exactly the right ordering. The multi-sentence privacy block is relevant but long and largely generic across the toolset, diluting focus on selection-relevant 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?

With an output schema present, return values need not be described (they are, harmlessly), and the only parameter is fully explained in prose. Error behavior and data-handling are covered, so nothing an agent needs to call this correctly is missing.

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 0% and the single parameter is undocumented in the schema, but the description compensates by giving the accepted key syntaxes with concrete examples (bare arXiv id, 'openalex:W...', 's2:...'). Minor gap: DOI-style keys are mentioned as inputs to check_citations but never as valid keys here.

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 first sentence names a specific verb and resource ('Look up one paper in the Reviewer Zero index') and pins the scope to a single record, which separates it from the search-style sibling find_prior_work. It also enumerates the returned fields, so an agent knows exactly what it gets.

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 states the required input and where valid keys originate ('a key returned by find_prior_work'), which implies the workflow: find_prior_work to discover, paper to fetch one. It does not, however, explicitly say when to prefer this over the citations or verify_quotes siblings that also operate on works.

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