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

With no annotations, the description carries the behavioral burden and does disclose that 'Page content is not stored.' It implies a read-only inspection by saying 'Return,' but omits other relevant behavior such as whether the URL is fetched live, what inputs other than url do, or any rate/error behavior.

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 short, front-loaded with the core result, and adds a meaningful privacy/behavioral note about page content not being stored. Both sentences earn their place.

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 9 optional parameters, no output schema, and several similar sibling tools, yet the description only addresses URL-host-scheme-status behavior. It does not explain how the other parameters relate to the tool, what the return format is, or why this tool should be chosen over a sibling.

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 input schema already documents each of the 9 parameters. The description adds only the 'for a URL' framing and does not clarify the many non-URL parameters in the schema, but the schema already covers their individual meanings.

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: 'Return host, scheme, and HTTP status for a URL.' This is clear and actionable, though it does not explicitly contrast with sibling tools such as 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?

There is no guidance on when to use this tool versus alternatives like fetch-status, browser-url-ok, or normalize-url. The description implies URL inspection, but does not state exclusions or conditions that should route an agent to another sibling.

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