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

With no annotations, the description bears the disclosure burden; 'Page content is not stored' is a useful behavioral guarantee and implies a read-only, non-persistent operation. However, it does not disclose network behavior, rate limits, or side effects beyond that single guarantee.

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 with the core result front-loaded and a single relevant privacy caveat. No filler 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?

The tool has nine optional parameters and many sibling URL tools, but the description does not state that only `url` is the relevant input or how the result is shaped beyond three fields. Schema descriptions compensate somewhat, but the overall selection context is thin.

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 each parameter's purpose, including which are discarded, is already documented. The description adds only the URL context and non-storage note, meeting but not exceeding the baseline.

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 names a concrete action ('Return host, scheme, and HTTP status for a URL') and resource, so an agent knows the primary output. It does not explicitly differentiate from sibling tools like fetch-status or normalize-url, so it falls short of a 5.

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 on when to choose this tool over siblings such as fetch-status, web-fetch, or browser-url-ok. The 'page content is not stored' note hints at a safe metadata use case, but there are no explicit when-to-use or when-not-to-use conditions.

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