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

With no annotations, the description carries the burden of behavioral disclosure. It does add one useful privacy-related behavior: page content is not stored. However, it does not disclose whether the tool makes a network request, follows redirects, or imposes any limits, leaving important behavioral traits unexplained.

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 extremely concise: two sentences, with the core output front-loaded and no redundant wording. Every sentence contributes useful information.

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 output schema, no annotations, and many siblings, yet the description only addresses the URL aspect. It does not explain the role of the other parameters, how they are discarded, or what the tool returns beyond host, scheme, and HTTP status. This leaves significant ambiguity for an agent attempting to call it correctly.

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 baseline is 3. The description does not add meaningful parameter semantics beyond the schema; it only mentions 'URL,' while the schema provides individual descriptions for all nine parameters. Some parameters appear unrelated to the core behavior, creating potential confusion that the description does not resolve.

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: it returns host, scheme, and HTTP status for a URL. It is clear about the core function, though it does not explicitly differentiate itself from similar sibling tools like fetch-status or normalize-url.

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?

No guidance is given about when to use this tool versus alternatives such as fetch-status, browser-url-ok, or normalize-url. The only contextual hint is 'Page content is not stored,' which implies a lightweight check but provides no explicit when-to-use or when-not-to-use direction.

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