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

With no annotations provided, the description must carry behavioral context. It does add one meaningful behavioral trait: 'Page content is not stored,' which is useful privacy information. However, it does not disclose whether the page is fetched, what happens to the other parameters, or anything about errors or side effects, so the disclosure is incomplete.

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 tightly written and front-loaded: the core purpose appears in the first sentence, and the privacy caveat earns its place in the second. It loses a point only because it may be too terse given the unusually broad and cryptic 9-property schema.

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?

There is no output schema, annotations, or required-parameter signal, and the description covers only the URL aspect while the schema includes unrelated-looking parameters like city, feed, json, and path. An agent is left without enough context to know what to pass or what the tool will do with those parameters. The description is not complete enough for safe invocation across the schema.

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 even though the description adds no parameter-level detail. The description only reinforces the 'url' concept by mentioning URL, host, scheme, and HTTP status, but it does not explain the many other schema properties or their relationship to the tool's stated purpose.

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 action ('Return') and a specific resource/output ('host, scheme, and HTTP status for a URL'). It clearly distinguishes this tool from siblings like normalize-url and web-fetch by naming the exact fields returned. The addendum that page content is not stored further clarifies what the tool does not do.

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?

No guidance is given about when to prefer this tool over the many sibling URL-related tools. The description implies a URL-checking use case but does not state alternatives, exclusions, or conditions such as 'use fetch-status for status only' or 'use normalize-url for normalization.'

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