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

With no annotations, the description bears full responsibility for disclosing behavior. It does reveal that query and fragment are dropped, which is a useful behavior. However, it omits critical details: what happens for invalid or non-HTTPS URLs, the exact output format, and the role of the other three parameters (host, json, zone) that appear in the schema. This omission is significant because an agent cannot predict how these extra parameters affect execution.

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 very concise (two short sentences) and front-loads the primary action and output. There is no fluff or redundancy. However, it is so brief that it leaves major gaps, but conciseness itself is well-handled—it just sacrifices completeness.

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 a tool with only one relevant parameter (url) but a schema listing four, the description should clarify which parameters are used and which are extraneous. It does not. There is no output schema, so the description should specify the return format (e.g., a string, an object with keys), but it only lists components. The description is insufficient for an agent to call the tool correctly, especially given the confusing extra 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 provides 100% description coverage, so the baseline is 3. However, the description adds no value beyond the schema—it does not even mention the 'url' parameter. More problematically, the description fails to reconcile the presence of 'host', 'json', and 'zone' parameters, which appear irrelevant to URL normalization. An agent cannot determine whether these are accepted, ignored, or required for other modes, creating confusion and reducing clarity beyond what the schema alone provides.

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 specific verb (return) and resource (URL), and specifies the output components (origin, host, path) plus a clear behavioral rule (dropping query and fragment). It is distinct enough from sibling tools, though it does not explicitly name alternatives. The presence of unrelated parameters in the schema slightly muddies clarity, but the core purpose is unambiguous.

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 given on when to use this tool versus alternatives like citation or domain-shape. There is no mention of prerequisites (e.g., must be HTTPS, must be a public URL) or conditions under which a different tool would be more appropriate. The description only states what it does, leaving the agent to infer usage.

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