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

With no annotations, the description carries the full disclosure burden. It discloses the HTTP method (HEAD) and that only status is returned, but it does not explain what happens with the many optional schema parameters (ref, city, json, query, etc.), how no URL is handled, or what error/status values are possible. The schema's parameter descriptions even suggest unrelated behaviors like normalization, validation, and hints, which the description never reconciles.

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?

One sentence, no filler, and the core behavior is front-loaded. The description earns its place with the method, scope, and return restriction.

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 eight optional parameters, no annotations, and no output schema, a single sentence is inadequate. It does not explain parameter selection, mutual exclusivity, return format, or how it relates to the sibling URL-status 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?

All parameters have schema descriptions, but the description adds no parameter meaning: it never identifies which parameter is the URL to HEAD or how the optional fields relate. The schema itself is inconsistent with the description (e.g., url is described as 'HTTPS URL to normalize or cite' rather than as a HEAD target), so the high coverage does not actually help an agent call the tool correctly.

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 operation: HEAD a public URL and return only the status. This is clear about the verb, resource, and output, and 'status only' distinguishes it from a full fetch. It does not explicitly differentiate from sibling URL-checking tools such as browser-url-ok or playwright-url-ok.

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 guidance on when to use this tool instead of alternatives. The only scope hint is 'public URL', with no mention of browser checks, no-body checks, or when web-fetch would be preferable.

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