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

No annotations are supplied, so the description carries the full disclosure burden. It usefully reveals that results include abstracts and PDF links and that each call costs 1 credit, but says nothing about ordering, pagination, result caps, or failure behavior for malformed queries.

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?

Two compact sentences: the capability and its return content come first, with the credit cost appended in parentheses. Nothing is redundant or buried.

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 simple two-parameter read tool with no output schema and no annotations, the description covers what it does, what it returns, and its cost. The remaining gaps (query syntax, pagination/limit semantics) are modest rather than blocking.

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 100%, so both parameters (query, limit with range 1-50) are already documented in structured form. The description adds no query syntax hints (e.g., field prefixes, boolean operators, category filters) that would go beyond the schema, so baseline 3 applies.

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?

"Search arXiv preprints" gives a specific verb and resource, and naming arXiv distinguishes it from pubmed_search and doi_lookup. It also states what comes back (abstracts, PDF links), though it never contrasts itself with papers_search, which may overlap.

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?

Usage is only implied via the arXiv domain name; there is no explicit when-to-use or when-not-to-use guidance and no mention of papers_search as the alternative for cross-source or non-arXiv queries. An agent can infer the source scoping but must reason about sibling overlap itself.

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