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

The annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint, which cover the primary behavioral aspects. The description adds that it returns 'metadata', giving a slight hint about the output, but does not describe side effects, errors, or pagination behavior beyond what the schema already notes. Given the high coverage by annotations, the description meets the baseline.

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, concise sentence that conveys the essential purpose without any extraneous information. It is well-structured, front-loaded with the resource and action, and includes the two key usage modes. No wasted words.

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 explains that the tool fetches metadata, which gives a general idea of the return content, but the absence of an output schema leaves the exact response format and pagination behavior unspecified. While the cursor parameter hints at pagination, the description does not elaborate. For a simple read-only metadata tool, this is adequate but not fully comprehensive.

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?

The schema provides 100% coverage with meaningful descriptions for all parameters (server, doi, date_or_range, cursor), including the mutual exclusivity of doi and date_or_range. The description does not add additional semantic nuance beyond the schema, so it neither enhances nor detracts from the parameter understanding. Baseline of 3 is appropriate.

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 function: retrieving bioRxiv/medRxiv preprint metadata, and explicitly specifies the two modes of lookup (by DOI or by date/date range). This is a specific, unambiguous purpose that distinguishes it from sibling tools like 'biorxiv_published' and 'biorxiv_publisher'.

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 does not mention when to choose this tool over alternatives, nor does it provide conditions or scenarios for use. It only describes the two input modes, which is implicit guidance but not explicit comparison to sibling tools. No direct 'use this when' or 'use that instead' guidance is given.

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