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

With no annotations provided, the description carries the full burden of disclosing behavior. It states that page content is not stored, which is a useful side-effect disclosure, but it omits other behaviors such as network calls, rate limits, or whether the operation is read-only. The transparency is minimal and does not cover the tool's full behavior, especially for the json and zone parameters.

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 a single, efficient sentence that front-loads the main action. It avoids redundancy and is appropriately sized for a simple tool, though it is terse and omits important context. The structure is clean, but the brevity contributes to incompleteness.

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 description is severely incomplete for a tool with four optional parameters and no output schema or annotations. It does not explain the json and zone parameters, does not describe the return format beyond the three fields, and provides no usage context. An agent would not know how to correctly set the non-URL parameters or when to use this tool instead of siblings.

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 schema provides descriptions for all four parameters (100% coverage), so the baseline is 3, but the description does not add meaning beyond the schema. Critically, the description focuses solely on URL handling while ignoring the json and zone parameters, creating confusion about their purpose. It fails to connect these parameters to the tool's overall behavior, so it does not enhance understanding beyond 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 description specifies a clear verb and resource ('Return host, scheme, and HTTP status for a URL'), which is a concrete purpose. However, it does not distinguish this tool from siblings like normalize-url or status-catalog, and it ignores the json and zone parameters, making the full scope of the tool ambiguous. The purpose is only partially clear.

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 provides no guidance on when to use this tool versus alternatives. It does not mention any exclusions or conditions, nor does it reference sibling tools. The only hint is 'Page content is not stored', which implies a lightweight check, but no explicit comparison or selection criteria is given.

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