web_search

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

The description reveals that the tool uses DuckDuckGo (no API key required) with an automatic fallback to a local SearXNG instance, which adds behavioral context beyond the readOnlyHint annotation. It does not mention rate limits or result freshness, but the core behavior is well disclosed.

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-loading the primary function in the first sentence and adding a crucial fallback detail in the second. Every word serves a purpose, making it highly efficient and easy to process.

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 description covers the core action, output components (titles, URLs, snippets), and fallback behavior. However, it omits mention of result count limit, caching, or error handling. Given the presence of an output schema, the description is fairly complete but could optionally address these points.

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 has 0% description coverage, meaning the description adds no meaning to parameters beyond the schema. It does not explain what 'query' or 'max_results' entail, nor their expected format. The description mentions 'top matches' but does not link it to the max_results parameter.

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 'Search the web' via DuckDuckGo and returns titles, URLs, and snippets. It uniquely identifies the resource (web) and action (search), distinguishing it from sibling tools like fetch_url or batch_fetch that handle individual URLs or file operations.

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 implies usage for general web search queries and mentions a fallback mechanism, but does not explicitly specify when not to use it or provide direct comparisons to siblings. The context from sibling names helps, but the guideline is not fully explicit.

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