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

With no annotations provided, the description carries the transparency burden and does add one meaningful behavioral fact: page content is not stored. It does not disclose other operational details such as redirect handling, caching, or error behavior, but the read-only character is reasonably clear.

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 the primary result front-loaded and a useful privacy/behavior note in the second sentence. No words are wasted.

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 covers the core input (a URL) and the return fields (host, scheme, HTTP status) in the absence of an output schema. However, with nine parameters, none required, and no mention of the other parameters' role, the description is a bit thin for an agent to confidently invoke it in all cases.

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?

Input schema coverage is 100%, so the schema already documents all nine parameters. The description adds only that the operation is 'for a URL' and does not clarify which of the optional parameters are expected or how the returned host relates to the host input, so the schema is doing the heavy lifting.

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 verb ('Return') and a precise result: host, scheme, and HTTP status for a URL. It is clear about what the tool does, though it does not explicitly contrast with sibling tools like 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 citation instead of related tools such as fetch-status, web-fetch, or normalize-url. The 'Page content is not stored' hint weakly implies a metadata-only use case, but no condition or alternative is stated.

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