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

With no annotations, the description carries the transparency burden. It discloses one useful non-obvious fact — page content is not stored — and lists the returned fields. However, it does not explain side effects, data retention, response format, or error behavior, so transparency is only partial.

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 short sentences with no filler. The first sentence front-loads the primary output, and the second adds a meaningful privacy note. Every sentence earns its 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?

For a tool with nine parameters, no output schema, and several closely related sibling tools, the description is too thin. It does not state the output format, which parameters are required, how the non-URL parameters relate, or when to prefer this tool over alternatives. An agent would likely need additional investigation before invoking 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?

The input schema provides descriptions for all nine parameters, so the baseline is 3. The tool description itself adds little beyond naming URL as the subject, and it does not help reconcile the many non-URL parameters with the stated URL-focused purpose. Schema descriptions do most of the semantic work.

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, so the core purpose is clear. It does not explicitly differentiate from close sibling tools like fetch-status or web-fetch, so it stops short of a 5.

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 choose this tool over the many nearby URL/status tools. 'Page content is not stored' hints at a behavioral boundary but does not state conditions, exclusions, or alternatives, leaving the agent to guess about routing.

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