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

Annotations only cover the generic safety profile; the description adds latency (waits for network up to 15s), an auth constraint (public pages only, no login), a failure-mode trigger (EXTRACTION_EMPTY), and a payment model ($0.01 USDC on Base via x402). The payment detail explains why readOnlyHint is false, so nothing is contradicted.

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?

Five short clauses, front-loaded with the differentiator ('Same output as /extract, but the page is first rendered'), and each remaining sentence carries distinct operational information. No filler.

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?

Covers the cost, latency ceiling, access limits, and the error condition that motivates use, and points to /extract for output shape. Minor gap: it doesn't say what is returned if the 15-second network wait expires, which matters for a tool with no output schema.

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 url, format, section, and maxChars are already fully documented in the schema. The description adds no parameter-level syntax or format detail, which is the expected baseline when the schema does the heavy lifting.

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 (extract rendered page text) and explicitly contrasts it with the sibling /extract, explaining the rendering difference. An agent can distinguish it from extract, screenshot, and text_extract without opening any 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 an explicit trigger condition: use when /extract returns EXTRACTION_EMPTY or too little text for a page readable in a browser. This names the alternative and the condition that selects this tool over it.

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