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

Beyond the readOnly/openWorld/idempotent annotations, the description discloses that no JavaScript executes, no browser is used, no account/key is required, and the tool never charges or takes payment. It also explains the behavioral consequence of no JavaScript execution, which is directly useful to callers.

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 long but front-loaded with the most important facts: free, no key, no account. Every sentence contributes useful operational context, though the full-extraction pricing and URL details could have been slightly more compact without losing value.

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 one parameter, no output schema, and strong annotations, the description fully compensates by enumerating the returned fields (HTTP status, final URL, byte count, title, character count, headings, JSON-LD, links, first 400 characters) and clarifying the no-JavaScript limitation. The tool is completely understandable without additional context.

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 100%, and the schema already describes 'url' as an absolute https address with a concrete example. The description confirms 'one public web page' but adds no further parameter-level semantics beyond what the schema provides, so the baseline of 3 is appropriate.

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 uses a specific verb and resource: it 'fetches one public web page and returns what a text extractor gets from it,' then enumerates the exact output fields. It clearly differentiates this preview tool from the separate paid full-extraction call, and the sibling tools are in a different email/security domain, so there is no ambiguity.

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 explicitly distinguishes the free preview from the full extraction, naming the alternative as a separate paid HTTP call with its own URL. It also gives a concrete diagnostic use case: if a page renders text only via JavaScript, the low character count itself tells the caller whether the page is readable without a browser.

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