web_search

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

With no annotations, the description must carry behavioral disclosure on its own. It reveals that Bing is tried first, DuckDuckGo is a fallback, and no API key is needed—useful behavioral traits. However, it does not describe the output format (beyond 'structured results'), error behavior, pagination, or rate limits. It adds some value but is not comprehensive, so 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?

Two sentences with zero filler. The core action is front-loaded, then the fallback and no-key facts are added efficiently. Every word earns its place; this is a model of concise writing.

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?

Given the tool has 4 parameters (1 required), no annotations, and an output schema, the description is incomplete. It fails to explain parameter meanings/format, does not guide tool selection relative to siblings, and does not describe the structure of results explicitly. While the output schema may cover return format, the absence of usage guidance and parameter semantics leaves an agent under-informed.

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 0%, so the description must compensate for all parameter ambiguity. It does not mention query, region, max_results, or safe_search at all. An agent gets no hint about what 'region' expects (e.g., language/country code) or the meaning of safe_search beyond its name. This is a significant gap.

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 verb ('Search') and resource ('the web'), and adds 'return structured results,' which is specific and distinguishes it from fetch/crawl/extract siblings. However, it does not explicitly name any sibling or contrast with alternatives, so it does not fully earn a 5.

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?

No explicit guidance on when to use this tool versus the sibling tools (web_fetch, web_crawl, web_extract). There is no mention of prerequisites, exclusions, or scenarios where this tool is inappropriate. The context is only implied by the name, so the description does not help an agent decide between alternatives.

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