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

With no annotations, the description carries the transparency burden. It does disclose one meaningful side-effect property: page content is not stored. However, it does not explain behavior for invalid URLs, authentication expectations, network-side effects, or which of the many parameters are actually checked.

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 short and front-loaded: the operation appears first, and the privacy note is useful rather than filler. It is slightly under-sized for a 9-parameter, zero-required tool, but as prose it is appropriately concise.

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 schema covers all parameters and the description states the output shape, an agent can probably make a basic call with the URL parameter. Still, with 9 optional parameters, no required combination, and several sibling URL tools, the description leaves important context about when and how to invoke it to inference.

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 itself adds little parameter-level meaning; saying 'for a URL' barely clarifies which of the 9 optional parameters matters, though the schema does document each individual 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 states a concrete operation: return host, scheme, and HTTP status for a URL, and adds a useful non-storage guarantee. It is clear, but it does not distinguish this tool from overlapping siblings like fetch-status, normalize-url, 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?

There is no guidance about when to prefer this tool over the many sibling URL/status tools, nor any conditional, exclusion, or preferred scenario. An agent must infer when 'return host, scheme, and HTTP status' is the right choice.

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