web_search_tool

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

No annotations are provided, so the description carries the behavioral disclosure burden. It discloses the result structure, pagination support, and graceful error handling ('returns them in the response rather than raising exceptions'). It does not mention rate limits or authentication, but for a local search tool these are minor omissions. It provides valuable behavioral context.

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 with no filler. The first sentence gives the core purpose, and the second adds essential behavioral details (result fields, pagination, error handling). It is front-loaded and efficiently worded.

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?

The tool has an output schema, so the description needn't detail return values. It covers the core function, result fields, pagination, and error behavior. It lacks explicit guidance on when to choose this over webpage_content_tool, but that is covered under usage guidelines. Overall, it is a well-rounded description for a search tool.

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 input schema already provides 100% coverage for query, page, and page_size. The description mentions pagination support generally, which reaffirms the page/page_size purpose, but adds no specific parameter semantics beyond what the schema already states. Baseline 3 is appropriate.

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 'Perform web search using SearxNG instance' – a specific verb and resource. It clearly states the tool searches the web and returns structured results (title, description, URL), distinguishing it from the sibling webpage_content_tool which fetches page content. No ambiguity.

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 clearly implies the tool is for web searches and provides context about results and pagination, but it does not explicitly mention when to use it over webpage_content_tool or state any exclusion criteria. The use case is clear, but alternative guidance is not explicit.

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