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

With no annotations, the description carries the behavioral burden. It does add a useful data-handling disclosure: 'Page content is not stored.' However, it does not state whether a network request is made, whether the operation is read-only, or how the many extra optional parameters are handled beyond the schema's own notes.

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 the primary return value front-loaded and no filler. 'Page content is not stored' earns its place as a useful behavioral note, making this appropriately concise.

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 nine optional parameters, no output schema, and no annotations, so this one-line description is insufficient for reliable invocation. It does not explain how multiple parameters combine, what happens when no parameters are provided, or what output is returned for non-URL inputs such as json, city, or zone.

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 all nine parameters. The description adds no additional parameter semantics beyond highlighting URL, and it does not clarify how to choose among the many optional inputs such as city, feed, json, zone, or query.

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 a specific action ('Return host, scheme, and HTTP status') and a clear target ('for a URL'), so an agent can understand the basic purpose. It does not differentiate this tool from siblings like fetch-status or normalize-url, and the nine-parameter schema suggests a broader behavior than the description acknowledges.

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 about when to use this tool instead of alternatives such as fetch-status, normalize-url, or web-fetch. 'Page content is not stored' is a behavioral note, not a usage condition, so the description leaves selection criteria entirely to inference.

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