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

No annotations are provided, so the description must carry the full burden of behavioral disclosure. It discloses that query and fragment are dropped, which is useful for the URL case, but it does not describe the behavior when other parameters are supplied (e.g., what happens when 'json' is passed? 'host'? 'zone'?). The tool appears to be multi-purpose, yet the description only covers one behavior, leaving the rest opaque.

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 concise: two sentences with no fluff. The primary behavior is stated upfront. However, it omits critical information about the other parameters, so while concise, it is not complete. Still, the brevity is a positive.

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?

Given the tool has four parameters that seem to represent distinct operations (URL normalization, host resolution, JSON validation, timezone handling), the description is severely incomplete. It only explains the URL path and provides no output schema or further context for the other modes. An agent cannot correctly call this tool for non-URL inputs based on the description alone.

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 descriptions cover all parameters (100%), but the tool description does not explain how the parameters relate or which to use in which context. The description focuses solely on 'url' and ignores 'host', 'json', and 'zone', implying they are irrelevant even though the schema suggests they trigger different behaviors. This is misleading and fails to add meaning beyond the schema's terse descriptions.

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 clearly states a specific verb and resource: it returns origin, host, and path for a URL and drops query and fragment. However, the input schema includes four distinct parameters (url, host, json, zone) that appear to represent separate functionalities (e.g., validate-json, timezone), and the description does not acknowledge these alternate modes or differentiate them from siblings like validate-json or timezone. Thus the purpose is clear only for the URL case, not for the tool as a whole.

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 on when to use this tool versus its siblings. The description does not mention that it can also handle host, JSON, or timezone inputs, nor does it state when to prefer this tool over validate-json or timezone. An agent would be unaware of the alternative use cases.

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