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

No annotations are provided, so the description carries the behavioral transparency burden. 'Page content is not stored' is a useful non-obvious disclosure, but the description does not clarify whether a network request is made, what HTTP method is used, or what other data (such as the discarded parameters) may be touched.

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 two short sentences with no redundant phrasing. The core behavior is front-loaded, and the privacy note 'Page content is not stored' earns its place by adding meaningful behavioral context.

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?

Given nine optional parameters, no output schema, no annotations, and a large sibling tool list, this two-sentence description is incomplete. It does not state which parameter to supply, what the return format is, or when this tool should be chosen over fetch-status or normalize-url.

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?

The input schema already describes each parameter at 100% coverage, so the baseline is 3. The description adds context that the URL is the relevant input and what result is produced, but it does not clarify that the other eight parameters are irrelevant, even though their schema descriptions repeatedly say 'discarded.'

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 states the action: 'Return host, scheme, and HTTP status for a URL.' This is a specific verb plus resource and gives the agent a clear sense of the tool's output. However, it does not explicitly differentiate this tool from URL-related siblings 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?

The description implies a use case: when you need host, scheme, and HTTP status for a URL. It does not provide when-not-to-use guidance or mention any alternative tools, so selection among the many URL-focused siblings is left mostly to inference.

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