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

With no annotations available, the description carries the behavioral burden and does convey key traits: it performs a HEAD request rather than GET, targets public URLs, and returns only a status. This meaningfully discloses the safety profile and response scope, though it remains silent on behavior for the other nine parameter types.

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, active verb, clear object, and explicit output. Every word contributes, with no filler or repetition of the tool name.

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 10-parameter tool with no annotations and no output schema, a single URL-focused sentence is inadequate. It does not explain whether to pass one param at a time, what the status return value looks like, or how this tool relates to the many sibling probe/check 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 description coverage is 100%, so per the rubric the baseline is 3. The description adds no parameter-specific semantics beyond reinforcing that the URL should be public; it does not compensate for or add to the already-documented parameters.

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 names the operation (HEAD), the resource (public URL), and the result (status only), which separates it from content-fetching siblings like web-fetch. However, it presents only one use case while the schema exposes ten heterogeneous parameters (json, city, zone, path, website, etc.), so it under-describes the actual tool surface.

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 phrase 'public URL' and 'status only' imply a lightweight pre-flight use for public endpoints, offering some usage context. Still, it gives no explicit when-to-use/when-not-to-use guidance and never names alternatives such as browser-url-ok or playwright-url-ok.

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