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

There are no annotations, so the description carries the disclosure burden. It adds one meaningful behavioral trait, 'Page content is not stored,' beyond the basic return values. However, it does not say that the tool fetches or contacts the URL, how redirects or errors are handled, or what the returned HTTP status semantics are.

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 primary behavior first and a secondary behavioral note second. There is no filler or repetition of schema data.

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 description only covers the URL-status case while the input schema exposes many unrelated-looking optional parameters (json validation, feed, city, path, ref) with no explanation of how they interact. With no annotations and no output schema, an agent lacks enough context to understand edge cases, error behavior, or whether this tool is multi-purpose.

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?

All 9 parameters have schema descriptions, so the baseline is 3. The description adds no parameter-level insight and does not explain how the URL-related output relates to the other optional fields (ref, city, feed, json, path), but schema coverage meets the threshold.

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 specific verb and resource: 'Return host, scheme, and HTTP status for a URL.' This clearly identifies the core output for a single URL. It does not explicitly differentiate from siblings like fetch-status or normalize-url, so it misses the top score.

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 'when to use' or 'use instead of' guidance. The note that page content is not stored implies a lightweight/privacy-preserving use, but it does not say when to choose this tool over browser-url-ok, web-fetch, or fetch-status, and it gives no exclusions.

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