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

Goes well beyond the annotations by disclosing billing mechanics ('Billed if any result returns; zero results or provider errors are not charged'), price and payment rail ($0.03 via x402, USDC on Base), per-page content caps (12K chars), and a prompt-injection warning that returned content is untrusted. These are exactly the operational facts an agent cannot get from readOnlyHint/openWorldHint.

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?

A single dense paragraph is front-loaded with purpose before mechanics, billing, and safety. Nearly every clause carries distinct information (return shape, limits, price, trust warning), though the run-on style slightly hurts scannability.

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 present, the description carries the full burden and does so: it enumerates the returned JSON fields (rank, url, title, snippet, ok/status, content, resultCount, fetchedOk), states content caps, and covers billing and trust caveats. An agent has everything needed to call and interpret it.

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 100%, so both q and n are already documented with their constraints and defaults. The description restates q (max 300) and n (1-5, default 3) but adds no syntax, format, or query-building guidance beyond the schema, so the baseline of 3 is appropriate.

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+resource ('Web search API with page contents') and adds the differentiator that top results are fetched as markdown, which separates it from siblings like fetch and extract. It stops short of naming those siblings explicitly, but the agent can tell it is a search-plus-content tool rather than a single-URL fetch.

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?

'For current info with sources' implies the use case but gives no explicit when-not conditions or named alternatives. An agent can infer it should call this for fresh web results, but the routing versus fetch/extract is left to inference.

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