Cite from an arXiv ID

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

Annotations already declare readOnlyHint=true and openWorldHint=true, and the description's 'on arXiv' confirms an external lookup. It adds useful output-shape detail (style name on the line above each citation, one .bib entry) but says nothing about behavior on invalid IDs, unversioned papers, or network failures.

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 core purpose is front-loaded in the first clause, followed by input enumeration and a concrete example. It runs long for a two-parameter tool and repeats the arXiv ID format already in the schema, but no sentence is 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?

For a read-only, two-parameter lookup with no output schema, the description supplies enough: supported styles, the 'all' response layout, and the bibtex variant. Gaps remain on the ris style (only in the schema) and on error behavior for malformed or nonexistent IDs.

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 does add meaning beyond the schema by explaining the 'all' output layout ('each one with its style name on the line above it') and the bibtex use case, but it also lists fewer styles than the schema (it omits 'ris'), creating a partial mismatch.

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 opens with a specific verb and resource: 'Look up an arXiv ID on arXiv and format the preprint citation' plus the exact list of supported styles. The arXiv-ID resource inherently separates it from siblings like cite_from_doi or cite_from_isbn, though no sibling is ever named.

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?

An example prompt ("Cite arXiv 1706.03762 in APA.") and the note that 'bibtex' should be passed for a reference manager give implied usage guidance. However, it never states when to prefer this over cite_from_doi, cite_from_url or format_citation, so an agent must infer routing from the resource type alone.

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