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

With no annotations provided, the description carries the transparency burden. It does disclose the HTTP method (HEAD) and the return scope ('status only'), which strongly implies a read-only, non-destructive operation. However, it does not mention redirect behavior, authentication needs, network side effects, or how the eight non-URL parameters are silently discarded.

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 a single, front-loaded sentence with no filler: 'HEAD a public URL and return status only.' It is concise and easy to parse. However, given the nine-parameter schema and the large sibling list, the brevity borders on under-specification rather than appropriately sized detail.

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 nine optional parameters, no annotations, no output schema, and several similar URL-related sibling tools, yet the description only covers the URL case. It omits how to select among the other parameters, what the 'status' response looks like, and how this tool differs from sibling URL checkers. This is not enough context for reliable selection and invocation.

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 the structured descriptions already define each parameter. The main description adds limited semantic value by clarifying that the url parameter is used with a HEAD request, but it does not help an agent understand the roles of ref, city, feed, host, json, path, zone, or query relative to the tool's purpose. This meets the baseline but does not compensate for the broader ambiguity.

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 names a specific action ('HEAD a public URL') and a clear output ('return status only'), so the basic purpose is understandable. However, the input schema exposes eight other optional parameters (ref, city, feed, host, json, path, zone, query) that are described as 'discarded after the check', which the main description never accounts for. This makes the tool's actual scope ambiguous and potentially misleading for an agent deciding what it can do.

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 guidance about when to use this tool versus sibling tools such as browser-url-ok, playwright-url-ok, normalize-url, or web-fetch. It also does not explain which of the nine optional parameters should be supplied or whether exactly one is expected. No when-to-use or when-not-to-use conditions are stated.

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