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

It discloses 'Page content is not stored', which adds privacy context beyond annotations (none exist). However, it omits that a network request is made, any rate limits, and how the other 8 parameters are handled. The single disclosure is useful but far from a complete behavioral profile.

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?

Two sentences with zero unnecessary words. The essential output and the privacy guarantee are front-loaded. No filler or repetition.

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?

For a tool with 9 optional parameters, no annotations, and no output schema, this description is too thin. It does not explain which parameters are needed, what happens when multiple are supplied, or whether there are prerequisites. The user would be confused about the purpose of many input fields.

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 coverage is 100%, so each parameter has a description. The tool description clarifies that 'url' is the relevant input and names the outputs, adding meaning beyond the schema's 'HTTPS URL to normalize or cite'. It does not, however, explain the roles of or interactions among the many other parameters.

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 the exact outputs (host, scheme, HTTP status) for a URL, which is a specific verb+resource. However, it does not distinguish itself from siblings like fetch-status or browser-url-ok, so it is clear but not fully differentiated.

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. The description only says what it returns, not when it should be preferred over fetch-status or normalize-url. It neither names alternatives nor gives a when-to-use/when-not-to-use.

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