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

With no annotations, the description carries the burden of behavioral disclosure. The explicit 'Page content is not stored' is useful, but other details such as network behavior, permission needs, limitations, or error cases are missing.

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 sentences long, puts the main purpose first, and uses one extra sentence for a meaningful side-effect disclosure. No filler or repetition is present.

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?

The tool has 9 parameters, no required fields, no annotations, and no output schema, yet the description only addresses 'a URL' without explaining which parameter to use, what to do with the non-URL parameters, or what happens with no input. Agent-facing ambiguity remains.

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 input schema already provides descriptions for all 9 parameters, so the baseline is met. However, the description adds no additional meaning about which parameter is primary or whether the many non-URL parameters should be used, discarded, or required.

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 opens with a clear verb and result: 'Return host, scheme, and HTTP status for a URL.' This makes the core operation obvious and separates it from unrelated siblings, though it does not explicitly contrast it with similar URL/status tools.

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 usage guidance is provided. The description does not say when to choose this versus fetch-status, normalize-url, browser-url-ok, or other URL-related siblings, and it offers no exclusions or preferences.

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