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

Beyond the readOnly/openWorld annotations, it discloses ad-free results, multi-engine automatic fallback, a 10-minute cache, per-call pricing ($0.005), and the x402 payment mechanism (USDC on Base or Solana). These are exactly the operational facts an agent needs before invoking a paid, cached, open-world call.

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-loaded with the core result shape, then follow-up tool, caching, and pricing in short declarative sentences. Every sentence carries distinct information; nothing is padded or restated from the schema.

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?

No output schema exists, yet the description fully specifies the return shape (title, URL, snippet, domain) and result ceiling. Cost, caching, engine fallback, and payment requirements round out everything needed to call and budget for this tool.

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 coverage is 75%, and the description adds meaning where the schema is thin: "up to 20 organic results" explains the limit ceiling, and the x402/payment sentence gives context for the otherwise cryptic tx parameter. The query and region parameters are left to the schema, which already documents them adequately.

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 and resource ("Searches the public web") and enumerates the returned fields (title, URL, snippet, domain, up to 20 organic results, no ads). The general-web scope implicitly separates it from news_search, wikipedia, and fetch, and the explicit pointer to /api/v1/fetch makes the follow-up path clear.

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 clear usage context: use it to get result links, then pair with /api/v1/fetch to read a result as Markdown. It does not state exclusions (e.g. use news_search for news, wikipedia for encyclopedic lookups), so the agent must infer the boundary against siblings.

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