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

Goes far beyond the annotations: 20,000-char cap per page with a truncated flag, per-page errors, a shared 20 s bound across pages, a failed page still being charged, 503 on failed search (not charged), typical 2-20 s latency, USD 0.025 price, 3 free searches per IP per UTC day, and an untrusted-data/prompt-injection warning. For a metered, latency-variable network tool this is exactly the disclosure an agent needs.

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?

Purpose is front-loaded in the first sentence, and every subsequent sentence carries distinct information (routing, limits, errors, price, safety). The middle section is dense and semicolon-heavy, packing many clauses into long sentences, which slightly hurts scanability but wastes nothing.

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?

For a paid, rate-limited, open-world tool with a non-trivial failure model, the description covers cost, free tier, timing, error semantics, content limits, and safety guidance. An output schema exists, yet the description still states the shape of the return, and no decision-relevant fact is missing.

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 the baseline is 3; the description adds behavioral meaning to n by tying it to the 20,000-character-per-page fetch and truncation flag, which explains the cost/latency tradeoff of raising it. q is left entirely to the schema, but that is adequate for a plain-text query.

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 ('Search the web and get the Markdown of the top results in one call') and immediately differentiates itself from the closest sibling, web_search, which returns links only. An agent can tell exactly what it gets back (title, url, snippet plus page Markdown) without opening the schema.

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 one explicit routing rule ('For links only use web_search') and an implicit when-not via 'Static fetch only, no JavaScript', which steers JS-dependent targets toward rendering siblings. It stops short of naming alternatives like fetch_page_contents or render_page, so coverage of the alternative space is partial rather than exhaustive.

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