web_search

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

With no annotations, the description carries the transparency burden. It discloses key behaviors: single API call, free/no API key required, supports English and Chinese, returns search result snippets. It does not mention rate limits or potential search restrictions, but covers the main user-relevant aspects.

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 well-structured with bullets and a separate usage notes section, front-loading the core purpose. Some redundancy exists between 'performs real-time web searches' and 'provides up-to-date information', and the bullet list is slightly verbose, but overall it remains focused and readable.

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 tool with no output schema, the description provides complete context: what it does, return format (titles, URLs, snippets), usage guidelines, alternative tools, language support, and auth requirements. It is sufficient for an agent to select and invoke the tool correctly.

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 the baseline is 3. The description does not add further meaning to the query or numResults parameters beyond what the schema already states (e.g., query content and result count with default). It names the tool's output but not parameter-specific behavior.

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 clearly states the tool performs real-time web searches using DuckDuckGo and returns titles, URLs, and snippets. It also explicitly distinguishes from siblings by directing URL retrieval to web_fetch and documentation queries to Context7, making the purpose unmistakable.

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 guidance on when to use this tool: for general web searches, current information, and queries beyond the model's knowledge cutoff. It also names alternatives: web_fetch for specific URLs and Context7 for API/library documentation, giving clear exclusions.

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