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

Since no annotations are provided, the description gets the full burden of behavioral disclosure. It explains what happens after fetching (Markdown conversion, boilerplate removal), quota and billing structure, and URL acceptance restrictions including rejection of private/internal networks. This goes well beyond anything the schema alone conveys.

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 compact and front-loads the core purpose in the first sentence. Subsequent sentences address endpoint binding, pricing, and URL constraints; every sentence contributes information and there is no redundant 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?

For a one-parameter read operation with no output schema, the description does enough: it explains return value, content cleanup behavior, rate limits, pricing, and input restrictions. The absence of information about errors, redirects, or non-HTML pages is a minor gap rather than a fatal omission.

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?

The schema covers the url parameter with 100% coverage, but the description adds meaning beyond the schema by restricting the allowed URLs to http/https, requiring absolute URLs, and explicitly rejecting private/internal hosts. That goes beyond the generic 'uri' format from the schema, so it boosts the baseline 3 to a 4.

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 gives a specific verb and resource: 'Fetch a URL server-side and return its main content as clean Markdown.' It also includes concrete details about stripping scripts/styles/nav/ads/boilerplate, which clearly distinguishes it from sibling tools like get_metadata and list_products.

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 provides clear operational context: this is for extracting readable content from a URL, with a wrapper around GET /v1/read and clear input constraints. It points to get_purchase_info for the x402 billing flow, but it does not explicitly state when to use an alternative like get_metadata instead of this tool.

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