Read bioRxiv/medRxiv preprint full text

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

Annotations already declare readOnly/idempotent/openWorld, and the description adds real value on top: the text is sourced from Europe PMC as JATS XML with PDF fallback, availability is delayed, and the failure mode is a descriptive error. It also discloses paging behavior via `truncated` and `next_offset`, fields that no output schema documents. It does not mention rate limits or typical response size beyond max_chars.

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?

Four sentences, each carrying distinct information: what is returned, accepted inputs, availability timing and failure mode, then paging. The most decision-relevant facts (output format and accepted identifiers) are front-loaded with no filler.

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?

With no output schema, the description must cover return values, and it does: plain text, source format, paging markers, and truncation handling. Combined with 100% parameter coverage and annotations covering safety, an agent has everything needed to call it correctly and to resume a truncated read.

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 earns above that by explaining the paging loop — inspect `truncated`, then feed `next_offset` back into `offset` — a relationship the schema alone cannot express. The three accepted id forms are restated from the schema rather than adding new meaning.

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?

States a precise verb and resource ("Return the full text of a bioRxiv or medRxiv preprint as plain text") and names the underlying source, so an agent knows exactly what comes back. It distinguishes itself from the metadata-oriented sibling biorxiv_get_preprint only implicitly via "full text"; no sibling is named explicitly, which keeps it just short of a 5.

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?

Gives concrete usage conditions: full text usually appears a few days after posting, and an error is raised if it is not yet available. Also explains how to continue reading long papers. It stops short of directing the agent to biorxiv_get_preprint for abstract/metadata or arxiv_get_full_text for arXiv items, so routing to alternatives is left to inference.

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