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

With no annotations, the description carries the transparency burden. It discloses that page content is not stored, which is a useful non‑obvious behavior. However, it does not mention network requests, potential failures, or other side effects, so transparency is partial.

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 concise and well‑structured, using two clear sentences. It front‑loads the action and output, and the added constraint is presented succinctly without unnecessary verbosity.

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 tool's apparent complexity (many parameters and no output schema), the description is severely incomplete. It does not explain the purpose of the extraneous parameters, the expected output format, or any error behavior. The agent would have little context to call it correctly beyond the basic URL case.

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 includes nine parameters, but the description only references a URL. Many parameters are marked as 'discarded after checks', yet the description does not clarify which parameter (likely `url`) is the primary input or how the other parameters relate to the described output. This leaves the parameter semantics vague.

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 the tool returns host, scheme, and HTTP status for a URL, using a specific verb and resource. It also adds a constraint about not storing page content. However, it does not explicitly differentiate from sibling tools like fetch-status, though the specific output set helps distinguish it.

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 gives no explicit guidance on when to use this tool versus alternatives. It implies a simple URL metadata check, but does not mention any conditions or exclusions, 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.