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

With no annotations, the description must carry the behavioral burden. It discloses the HTTP method (HEAD, no body), the access context (public URL), and the output scope (status only). It does not specify the exact status format or edge-case behavior, but it is honest and useful for a simple read-only check.

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. Every word contributes to the core message: operation, target, and output scope.

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 is enough to invoke the tool with a url and understand that the result is a status. However, with 9 optional parameters, no output schema, and no annotations, an agent may be unsure what 'status' precisely means and whether any non-url parameters affect the result.

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 schema already documents each of the 9 optional parameters. The description adds little beyond indicating that a URL is the relevant input, which is already present in the url parameter description.

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 identifies a specific operation: HEAD a public URL and return status only, with the verb and resource stated precisely. It does not explicitly differentiate from siblings like web-fetch or browser-url-ok, so it is not a 5.

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 implies the intended use case: checking a public URL's status without retrieving content. However, it provides no explicit when-to-use versus alternatives guidance, such as using web-fetch when content is needed.

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