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

No annotations are provided, so the description carries full responsibility for behavioral disclosure. It does not mention side effects, whether the operation is read-only, rate limits, or expected return behavior. It only gives usage modes and engine list, which is not enough given zero annotation support.

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 three sentences, front-loaded with the core action, and every sentence adds necessary information: purpose, usage modes, and engine constraints. There is no redundant or filler 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?

The description gives a good high-level overview and engine guidance, but there is ambiguity around parameter combinations and precedence, especially since all parameters are optional. The output schema covers return values, so that gap is acceptable, but the input semantics are incomplete.

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%, so the description must compensate. It explains the two invocation groups (DOI vs author_name + candidate_index + paper_index) and acceptable engine values, but does not define the meaning or format of individual parameters like candidate_index or paper_index.

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 states the tool's purpose with 'Expand a paper into its references', which is a specific verb+resource. It also identifies itself as 'the main edge-expansion tool for traversing the literature graph', distinguishing it from sibling tools that handle other operations like abstracts or search.

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 provides explicit usage modes: 'Use with a DOI or with author_name + candidate_index + paper_index', and engine selection instructions. It positions the tool as the main expansion tool, implying when to use it, though it doesn't explicitly say when not to use alternatives.

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