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

Annotations are absent, so the description carries the behavioral burden. It does disclose one meaningful behavior: 'Page content is not stored.' That suggests a privacy/read-only quality, and 'Return' implies a read operation. However, it does not address handling of the many extra parameters, potential side effects, errors, or permission requirements, leaving a clear transparency gap.

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 and front-loaded: the main purpose appears in the first sentence and the behavioral note in the second. There is no fluff, but the brevity sacrifices context needed to handle the parameter-rich schema.

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?

This is a 9-parameter tool with no output schema and substantial sibling overlap. The description only explains a URL-shaped use case and leaves the other parameters unexplained in the tool-level description. It is not complete enough for an agent to confidently invoke the tool across the full schema.

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 adds no new parameter meaning beyond 'URL', which maps to the 'url' property. It does not explain how to use the other 8 optional parameters or clarify which ones are needed to satisfy the stated purpose.

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 outcome: 'Return host, scheme, and HTTP status for a URL.' It uses a clear verb and resource, and the additional 'Page content is not stored' hints at scope. However, it does not differentiate this from similarly named siblings like fetch-status, normalize-url, or domain-shape, so an agent may not know why citation is the right choice.

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 sibling tools. There is no mention of alternatives, disqualifying conditions, or which of the 9 optional parameters should be present for the tool to be meaningful. An agent is left to infer that 'url' is the primary parameter, but the description does not say so.

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