Web Search

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

With no annotations provided, the description must carry the burden. It discloses the return format ('clean list of titles, URLs, snippets') and the engines used, which is some behavioral transparency. However, it omits details like rate limits, error behavior, or how the network-layer blocking (block_media) affects results, which would be useful beyond the schema. This is adequate but not rich.

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 a concise two-sentence summary that front-loads the action ('Search the web') and immediately explains the output and ideal use cases. Every sentence serves a purpose with no wasted words, achieving excellent conciseness and structure.

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 is a simple search operation, and the description covers purpose, output, and use cases. Since there is no output schema, it compensates by describing the return list. It does not mention limitations (e.g., engine-specific differences, pagination) but those are not critical for basic usage. Overall, it is complete for the tool's complexity.

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 100% coverage, meaning every parameter (query, engine, region, block_media, max_results, safe_search) already has a description. The tool description adds no additional parameter-specific meaning beyond what the schema provides. Per the baseline rule, a score of 3 is appropriate when the schema does the heavy lifting.

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's function: 'Search the web using DuckDuckGo or Google' and describes the output as 'titles, URLs, and snippets.' It defines a specific verb and resource, but does not explicitly differentiate from the sibling tool 'webfetch', which searches vs. fetches. The phrase 'finding URLs' hints at a distinction but lacks direct comparison.

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 clear use cases ('researching general knowledge, news, and finding URLs') which tells when to use the tool. However, it does not discuss when not to use it or mention the alternative 'webfetch' for fetching specific pages. This is clear context without exclusions, so it earns a 4.

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