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

The annotations already signal readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false. The description adds the key behavioral detail that it returns a list of cited DOIs, which is helpful but not deeply behavioral (e.g., no mention of pagination, error handling, or the output format). Given high annotation coverage, a 3 is appropriate.

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 a single sentence containing the key definition, usage examples, and explicit scoping. It is front-loaded with the purpose and ends with intended use cases. No redundant information; every word earns its place.

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?

Given the tool has one parameter, a clear purpose, and an output schema (not shown but present), the description is fairly complete. It doesn't explain the output format, but the output schema likely covers that. It does not mention edge cases like invalid DOIs or rate limits, but for a read-only single-parameter tool, this is acceptable.

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 for the single 'doi' parameter. The description explicitly states the 'doi' parameter is the paper whose references are returned, adding semantics beyond the bare schema. Since there is only one parameter and the description explains its role clearly, this compensates for the lack of schema descriptions.

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: it returns DOIs cited by a given DOI (the reference list/bibliography). It uses specific verbs ('cite', 'references') and explicitly contrasts with the sibling 'citations' (which presumably returns papers that cite the given DOI). This distinguishes it from siblings like 'citation' and 'citation_count'.

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 use cases: 'citation-graph traversal, literature review, source tracking.' It implies the tool is for finding cited works, not for finding citing works. However, it does not explicitly name alternative tools (like 'citations' or 'citation_count') or state when NOT to use it, but the context signals from sibling names and the description's clarity make this less critical.

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