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

With no annotations, the description carries the full behavioral burden and does disclose the non-obvious access model: no account/API key/subscription, paid per call in USDC via x402. It also describes the return payload (titles, URLs, descriptions, result age). It stops short of covering rate limits, error behavior, or result caps, which for a paid per-call tool would be useful.

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?

Front-loads the core action and keeps to three compact clauses with no filler paragraphs. A few phrases ("ready to cite, summarize or read further", "powered by Brave Search") lean promotional rather than informational, but the text is efficiently sized overall.

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?

With no output schema and no annotations, the description does the heavy lifting well: it describes return fields, usage contexts, and the payment/access model. The one notable hole is the undocumented num_results parameter, but for a simple two-param search tool the coverage is otherwise strong.

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. It clarifies the semantics of "query" as a natural-language string, but says nothing about "num_results" — its range, default, or valid bounds. Half the parameters remain undocumented in both schema and description.

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?

States a specific verb (search) and resource (live web), and pins down the source as "Brave's independent web index," which meaningfully separates it from the sibling search-tavily. It does not name the sibling tools directly, so the differentiation is implicit rather than explicit.

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?

Gives concrete usage contexts ("research, fact-checking, news and docs lookups, price and competitor checks inside agent workflows"), which is clear when-to-use guidance. It offers no when-not-to-use conditions or comparison against the other search siblings (search-tavily, web-search, web-answer), leaving the routing decision partly to inference.

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