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

Annotations already establish that this is a read-only, open-world operation. The description adds useful behavioral context beyond that: pricing, free failed calls, the x402 quote flow, and that it reports when the page was longer than the summarized portion.

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?

The description is front-loaded with the core purpose, followed by truncation behavior and payment details. Every sentence carries useful information and there is 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?

With no output schema, the description does describe key return elements: summary, title, final URL, and truncation notice. It also covers payment behavior, though it could say more about summary format or error handling beyond failed calls being free.

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 schema already documents `url`, `payment`, and `max_words` thoroughly. The description reinforces the payment workflow but adds little parameter-level meaning beyond what is already in the schema.

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?

The description states a specific verb and resource: read a web page and return a summary plus title and final URL. It is clear what the tool does, though it does not explicitly distinguish itself from sibling tools like read_page or screenshot_page.

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 payment workflow is clearly specified: call without `payment` to get a quote, then sign and call again. However, there is no guidance on when to use this tool instead of alternatives such as read_page, so the agent must infer the use case.

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