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

Annotations already declare readOnlyHint=true and openWorldHint=true, covering the safety and open-world nature of the tool. The description adds value by specifying the returned fields (title, author, abstract, etc.) and repository scope, but does not disclose pagination, rate limits, or no-result behavior. With annotations handling the core behavioral transparency, a 3 is appropriate.

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 description is two sentences long, front-loaded with the primary function, and contains no filler. It efficiently conveys purpose, output, and typical use cases.

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 search tool, the description is largely complete: it states what it searches, what it returns, and when to use it. The schema and annotations cover parameters and safety. It lacks explicit comparison to the sibling tool and edge-case behavior (e.g., empty results), but overall it is adequate for a well-specified tool with rich structured metadata.

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%: both 'query' and 'max_results' have descriptive text. The tool description adds no parameter-level detail beyond what the schema already provides, so the baseline 3 is justified.

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 states a specific verb ('Search') and resource ('arXiv preprint repository') and lists the academic fields covered. It also enumerates the return fields, clearly distinguishing it from the sibling tool by repository. This is a clear, specific purpose statement.

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 description provides explicit user contexts ('cutting-edge research, literature review, or staying current in academic fields') that indicate when to use the tool. However, it does not mention when not to use it or contrast with search_google_scholar, so it lacks explicit alternatives. This aligns with a 4: clear context without exclusions.

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