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

With no annotations at all, the description carries the full behavioral burden and does well: it discloses the $0.01 per-call price, the USDC-on-Base (eip155:8453) payment rail, exactly where the payment goes (params._meta["x402/payment"]), and the HTTP method and endpoint. It stops short of rate limits, retry/failure behavior, or whether JS-rendered pages are supported.

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 capability, then invocation modes, then pricing/transport — a sensible ordering with almost no filler. The only waste is repeating '$0.01' twice in adjacent sentences.

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 3-parameter, no-output-schema tool with zero annotations, the description supplies the crucial missing context: cost, payment mechanism, transport, and batch ceiling. What remains absent — return shape specifics beyond a summary list, and links_max interaction with batch mode — is minor.

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 only restates the batch limit ('up to 10 URLs') already documented in the schema and adds no semantics for links_max or for the GET-vs-POST applicability of url versus urls.

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 pair — converting public web pages into markdown — and enumerates the outputs (metadata, headings, link inventory), which distinguishes it in substance from a plain reader. It does not name or differentiate against the very similar siblings web_extract__extract, webread__read, or agentkit__extract, so an agent must still guess which of those to pick.

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?

The description makes the single-URL vs batch-up-to-10 modes explicit, which is genuine usage guidance for choosing an invocation shape. However it offers no when-to-use/when-not versus the many sibling extraction tools, and no statement of the prerequisite that the page must be public and http(s).

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