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

With no annotations, the description carries the behavioral disclosure burden. It does disclose a meaningful behavior—'Page content is not stored'—which addresses data retention. However, it omits network behavior, failure modes, redirect handling, and whether any external request is made.

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 the core output front-loaded and the privacy guarantee adding real value. Every word earns its place; there is no redundancy or filler.

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?

For a tool with nine optional parameters and no output schema, this description is too thin. It only addresses the URL aspect, does not clarify how the other parameters relate, and lacks output formatting or failure behavior. An agent would struggle to select it confidently among overlapping sibling tools.

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 coverage is 100%, so the baseline is 3. The description adds no parameter-level guidance and only reinforces that the tool operates on a URL. The purpose of the other optional parameters is not explained by the description, leaving the agent to rely entirely on the schema's terse per-parameter descriptions.

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 states a specific action ('Return host, scheme, and HTTP status') on a specific resource ('a URL') and adds a relevant privacy note. It is not a tautology, but it does not differentiate this tool from overlapping siblings such as normalize-url or fetch-status.

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 when to use the tool: when an agent needs host, scheme, and HTTP status for a URL. However, it gives no explicit when-not-to-use guidance and names no alternatives, even though several sibling tools appear related.

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