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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It does add a useful privacy guarantee ('Page content is not stored'), but it omits other relevant traits such as whether a network request is made, error behavior, or rate-limit implications.

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 short sentences with no filler. The purpose is front-loaded, and the second sentence adds a meaningful behavioral caveat rather than repeating the 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?

Despite having 9 parameters and no output schema or annotations, the description is extremely brief. It does not explain the role of the other parameters, error cases, return format details, or how this tool relates to its siblings. The schema covers parameter meanings, but the overall context is incomplete for such a multi-purpose-looking tool.

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 beyond the schema; it only highlights that the tool works 'for a URL', which the schema already conveys for the url parameter.

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 identifies the verb ('Return'), the resource ('a URL'), and the outputs ('host, scheme, and HTTP status'). It is specific enough to understand the core function, though it does not explicitly differentiate itself from siblings like normalize-url, fetch-status, or web-fetch.

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 use this tool versus its many siblings. The description does not state which conditions favor citation over fetch-status, normalize-url, or web-fetch, leaving the agent to infer the appropriate use case.

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