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

The description mentions the cost ('[$0.03/call]') and the backend sources ('Keyless via OpenAlex and Semantic Scholar'), providing transparency about pricing and data origin. It does not indicate any destructive or state-changing behavior, implying a read-only operation, though it does not explicitly state this.

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 but dense, containing purpose, parameters, cost, and an example in a single paragraph. It is well-structured with clear parameter definitions and an example, though the repeated mention of 'citation lookup' could be trimmed slightly without losing meaning.

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?

It covers the tool's purpose, accepted identifiers, parameters, cost, and an example, which are sufficient for an agent to decide to use it. It does not describe the exact return format or error handling, but those are not essential for a straightforward lookup and are likely handled by the tool's standard response.

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?

Although the schema only defines a generic 'params' object, the description enumerates all relevant parameters (id, doi, ref_limit, cite_limit) with their purposes and provides a concrete example. This fully compensates for the schema's lack of parameter detail.

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 tool as a citation lookup and reference list for a paper, specifying that it returns references and cited-by lists given a DOI, arXiv id, OpenAlex id, or PMID. It also states the intended use case: 'for bibliography building and citation lookup', which removes ambiguity.

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?

The description provides clear input options and the operations performed, such as returning references and cited-by works. It does not explicitly contrast with sibling tools like papers or related_papers, but the specific terminology 'bibliography building and citation lookup' gives a strong contextual hint for when to invoke this tool.

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