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

With no annotations, the description carries the behavioral burden. It does disclose one important trait: 'Page content is not stored.' However, it does not mention network behavior, redirects, rate limits, or what happens to the seven input parameters, leaving several behavioral aspects implicit.

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 filler; the core output is front-loaded and the non-storage guarantee is a worthwhile second sentence. It is as concise as possible for the information it provides.

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?

Given seven optional parameters, no output schema, no annotations, and a cluster of sibling URL tools, this description is too sparse. It doesn't explain which parameters to pass, the return shape, or how this choice differs from fetch-status/web-fetch, so an agent has incomplete context for correct invocation.

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%, so the schema already documents each parameter, earning a baseline of 3. The description adds no mapping between the stated URL behavior and the many non-URL params (ref, city, feed, json, path), though their schema descriptions do say they are discarded.

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 ('Return') and names a concrete resource: host, scheme, and HTTP status for a URL. It is clear enough to identify the core operation, but it does not explicitly contrast with sibling URL tools such as fetch-status or normalize-url, so differentiation is left to inference.

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 rather than the many related siblings (fetch-status, web-fetch, normalize-url, browser-url-ok). 'For a URL' gives context but no exclusions, alternatives, or prerequisite conditions, so an agent cannot reliably choose it among similar tools.

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