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

No annotations are provided, so the description carries the burden. It adds one meaningful behavioral guarantee—'Page content is not stored'—and specifies the limited output. However, it does not disclose whether a live network request is made, how errors are handled, or whether any page content is fetched at all.

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?

Two sentences, front-loaded with the main result and followed by a relevant privacy note. Every word earns its place; no fluff or repetition.

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 tool with 9 optional parameters and many sibling tools, the description is minimally sufficient: it states the output, the key input (URL), and a behavioral guarantee. It does not cover invalid URL handling, the live request nature, or directly disambiguate between related siblings, though the schema and output statement cover the basics.

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 baseline applies. The description clarifies the output produced from the url parameter but adds no detail beyond the schema's explicit per-parameter descriptions, including the discarded/ignored parameters.

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: 'Return host, scheme, and HTTP status for a URL.' It also differentiates from content-fetching tools by adding 'Page content is not stored,' making the tool's focused role clear even without naming siblings.

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 implies use for URL citation/metadata retrieval and notes content is not stored, but it does not explicitly state when to prefer this tool over alternatives like fetch-status, normalize-url, or web-fetch. No exclusions or alternative tool names are given.

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