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

The description discloses one behavioral trait: 'Page content is not stored', which is useful privacy information. However, with no annotations provided, the description carries the full burden of behavioral disclosure. It does not mention anything about the behavior for the 'json' or 'zone' parameters, nor does it state whether the operation is read-only or what happens with invalid inputs. The single trait is a positive but incomplete disclosure.

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 short sentences with no filler. The primary action and the key privacy note are front-loaded. Every sentence earns its place, making it highly 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?

The tool has four parameters, some of which (json, zone) are clearly unrelated to the stated purpose of returning host/scheme/status. The description does not explain the full scope of the tool or how the other parameters fit in, leaving significant gaps. With no output schema and no annotation coverage, the description is not complete enough for an agent to use this tool correctly across all its parameters.

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 covers 100% of parameters, so the baseline is 3. However, the tool description only addresses the 'url' parameter, ignoring 'host', 'json', and 'zone'. It does not add any meaning for these parameters beyond what the schema already provides, and its narrow focus may mislead an agent into thinking they are irrelevant. Since the description does not compensate for the schema's coverage and actually creates confusion, a 2 is warranted.

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 clear action ('Return host, scheme, and HTTP status for a URL') with a specific resource. However, it does not differentiate from sibling tools like 'normalize-url' or 'status-catalog' which could overlap in function. The purpose is clear but not uniquely positioned among 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?

No guidance is provided on when to use this tool versus alternatives such as 'normalize-url' or 'status-catalog'. There is no mention of when it is appropriate or inappropriate, and no exclusions or alternative routing. The agent is left to infer usage from the description alone.

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