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

With readOnlyHint, openWorldHint, and idempotentHint already set, the description goes well beyond them by disclosing batch behavior, per-DOI failure reporting with reasons, retryable flags, rate-limit wait times, and the fact that all revisions are returned in one response. This is rich, non-obvious behavioral context that annotations alone do not provide.

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 front-loaded with the core purpose and every subsequent sentence adds necessary behavioral or constraint information. It is dense but not bloated; each sentence 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?

For a batch lookup tool with an output schema, the description covers the essential operational details: what is fetched, how revisions are returned, server selection, failure semantics, retryability, and DOI format requirements. Nothing critical is missing for an agent to select and invoke this tool correctly.

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 coverage is 100%, so the baseline is 3. The description adds value by specifying the DOI pattern (10.NNNN/…), the default behavior of server='both', and how failures are handled per DOI. These details go beyond the schema's parameter descriptions without duplicating them.

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 names a specific action ('Fetch full metadata, abstract, all revision history, JATS XML full-text links, and published-journal DOI') and a specific resource (preprints by DOI). It is clear and detailed, but it does not explicitly differentiate itself from siblings like biorxiv_get_fulltext or biorxiv_get_published_version, which could have overlapping responsibilities.

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 gives clear context for when to use the tool: given one or more preprint DOIs, it returns metadata and revisions. It also explains the server='both' default behavior. However, it does not explicitly state when NOT to use it or which sibling to choose instead, so it lacks explicit exclusion guidance.

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