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 that page content is not stored, which is useful, but it does not mention whether a network request is made, how redirects are handled, or any failure modes.

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 extremely concise, with only two sentences and no redundant wording. The core behavior is stated before the secondary note about storage.

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 the simple wording, the tool has 9 optional parameters and no annotations or output schema, and the description does not explain which parameters are relevant or how they relate to the stated purpose. This leaves the agent with significant ambiguity about how to call the tool correctly.

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?

The schema descriptions cover all 9 parameters, so the baseline is 3. The description adds no parameter-level detail and does not clarify why unrelated parameters such as ref, city, zone, or query are present, but it does not contradict the schema either.

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 action ('Return'), the resource ('a URL'), and the specific outputs (host, scheme, HTTP status). It does not explicitly compare itself with siblings such as fetch-status or normalize-url, so it stops short of full differentiation.

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 tools, nor when not to use it. The description states what it does but leaves usage context entirely implicit.

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