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

With no annotations provided, the description must carry the behavioral burden. It adds the useful privacy guarantee 'Page content is not stored' and implies a read-only status check, but it does not disclose whether the URL is fetched, how errors or redirects are handled, or what happens when json or zone inputs are supplied. This leaves meaningful behavioral ambiguity.

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 two sentences, with the core purpose front-loaded and no filler. The second sentence contributes a relevant behavioral guarantee. It is appropriately concise and well-structured.

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 an unannotated tool with four optional parameters and no output schema, this description is incomplete. It omits usage guidance, the roles of json and zone, and any detail about the return object beyond three fields. The sibling set and schema complexity suggest more context is needed for correct invocation.

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 because the schema already documents url, host, json, and zone. The description adds no parameter semantics beyond mentioning the URL and does not explain how json or zone relate to the tool's purpose. It neither enriches nor contradicts the schema.

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 first sentence clearly states a concrete action and resource: 'Return host, scheme, and HTTP status for a URL.' It is specific and understandable on its own. However, the schema also includes json and zone parameters that the description never mentions, so the full scope of the tool is ambiguous, and it does not differentiate from siblings.

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?

The description gives no guidance on when to use this tool versus alternatives like normalize-url, status-catalog, validate-json, or the timezone tools. There are no stated conditions, exclusions, or preferred contexts, so an agent cannot decide between siblings based on this text.

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