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

With no annotations, the description carries the full burden; it does disclose the per-call x402 payment cost, which is valuable and non-obvious behavioral context. It does not say what happens on non-article pages, whether extraction can fail, or how the payment handshake behaves beyond what the x_payment schema field already says.

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 well-formed sentence with the payment tag front-loaded and no filler. Appropriately sized for a two-parameter tool, though the bracketed payment marker slightly obscures the main verb.

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?

The tool is simple (two parameters, no output schema, no annotations), and the description covers what it produces at a high level (Markdown). It is missing the return shape (plain text vs. object with title/body) and behavior for pages where Readability yields no main content, which an agent needs to interpret results.

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 coverage is only 50% and the description adds nothing about parameters. The url parameter has no description anywhere, and the only parameter documentation (x_payment) lives in the schema, not the description, so the description fails to compensate for the coverage gap.

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 (extrae) and resource (contenido principal de un artículo/página), plus the mechanism (Readability) and output format (Markdown). An agent can distinguish it from web_tools_metadata or web_tools_screenshot, though the overlap with docs_tools_to_markdown is not addressed.

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?

Usage is implied by 'artículo/página' but there is no explicit when-to-use, no exclusions (e.g., non-article pages, PDFs), and no mention of alternatives such as web_tools_metadata or docs_tools_to_markdown. The payment requirement is stated but not framed as a decision factor.

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