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

With no annotations provided, the description carries the burden of behavioral disclosure. It usefully states that page content is not stored, but it does not mention side effects such as making an HTTP request, potential failures, or how it handles invalid URLs.

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 two short sentences with no wasted words. The primary action and output are front-loaded, and the privacy note is concise and relevant.

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 description states the essential return values and a key behavioral guarantee, which is minimally sufficient for a simple URL check. However, the 9-parameter schema, zero required parameters, and lack of an output schema leave the agent without explicit guidance about return format or which parameters to prioritize.

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 is 3. The description adds no parameter-level meaning, and the schema includes many distractor optional parameters; however, the url parameter is clearly described as the HTTPS URL to normalize or cite.

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 clearly states the tool's action and output: return host, scheme, and HTTP status for a URL. The note that page content is not stored helps distinguish it from content-fetching tools, though it does not explicitly differentiate it from fetch-status or normalize-url.

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?

There is no guidance about when to use this tool versus sibling tools such as fetch-status, web-fetch, normalize-url, or browser-url-ok. The agent must infer the intended use case from the description alone.

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