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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is known. The description adds behavioral detail by specifying the return fields (titles, authors, abstracts, dates, PDF links), which helps the agent anticipate the output. It does not mention any limitations like metadata-only search, but that is not critical.

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 crisp sentences without fluff. The first sentence covers purpose and output, the second covers usage. All sentences earn their keep.

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 two simple parameters, full schema descriptions, and read-only annotations, the description provides sufficient context. It lists output fields and usage, making it complete for a search tool without needing an output schema.

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 covers both parameters with descriptions, so coverage is 100%. The description reinforces the query domain but adds no new parameter semantics beyond the schema. 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?

The description opens with 'Search arXiv for academic papers in computer science, machine learning, AI, physics, and mathematics,' which clearly states the action, resource, and domain scope. It differentiates from sibling search tools like search_google_scholar by naming arXiv specifically and listing return fields.

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 phrase 'Use for researching algorithms, ML techniques, or emerging CS topics' provides clear usage context. It does not explicitly name alternatives like search_google_scholar or exclude non-academic queries, so it stops short of a full 5.

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