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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered; the description adds relevance ranking and enumerates the returned fields (id/link, title, date, authors, abstract), which is valuable since there is no output schema. It doesn't mention rate limits or the 20-result cap, keeping it short of a 5.

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?

Three sentences, zero padding, with purpose first and the alternative and return values following in order of decision relevance.

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 two-parameter read-only search with full schema coverage and good annotations, the description covers purpose, routing and return shape. Only minor gaps remain (pagination/limits, dedup or sorting options) that an agent would rarely need before calling.

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% (query example and limit 1-20 range are documented), so the baseline is 3. The description adds that the query matches across title, abstract and authors, which is useful semantic detail but modest beyond the schema.

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 specific verb ("Search") and resource ("arXiv research papers") plus the searched fields (title, abstract, authors) and ranking behavior. It is immediately distinguishable from wikipedia_search and other siblings.

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?

Explicitly routes the agent: "Use it for academic preprints; use wikipedia_search for general background." That names an alternative and the condition selecting it, though other search siblings (github_search_repos, hackernews_search) are not contrasted.

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