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

With no annotations provided, the description carries the full burden of behavioral disclosure. It does add one meaningful behavioral trait: page content is not stored, which is a privacy-related guarantee. However, it does not disclose other important behaviors such as whether any input is retained, whether network access is required, or whether there are side effects beyond returning results.

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 primary function is stated first, and the key behavioral caveat about not storing content is included second. Every sentence earns its place.

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 the rich input schema with 9 optional parameters and no output schema, the description is somewhat thin. It clearly states the return values, which is good, but it does not clarify that only the url parameter is relevant or that the other parameters are ignored/discarded. The schema helps, but an agent could still be uncertain about which parameters matter for a citation call.

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 tool description only mentions 'URL'. The schema already documents each parameter, including which values are discarded. The description adds little semantic meaning beyond identifying url as the key input.

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 precise result set: host, scheme, and HTTP status for a URL. This clearly distinguishes the tool from siblings like normalize-url or fetch-status, which focus on narrower or different outputs. The additional 'Page content is not stored' clause further separates it from web-fetch or browser-url-ok.

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?

The description implies the tool should be used when an agent needs host, scheme, and HTTP status for a URL. However, it does not explicitly state when to prefer this tool over sibling tools like fetch-status or normalize-url, nor does it mention any exclusions or alternative routing. Usage context is present but only by inference.

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