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. The description does disclose one behavior: query and fragment are dropped. However, it says nothing about how the other eight parameters (e.g., ref, city, feed, json) are handled, even though their schema descriptions indicate they are 'discarded after a check.' This omission leaves the tool's actual behavior for non-URL inputs completely opaque, and the return format is also undisclosed.

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 sentence, which is concise and front-loaded with the primary behavior. However, given the tool's 9-parameter schema and no output schema, this brevity borders on under-specification. It omits critical context about non-URL parameters and output, making the description efficient but incomplete.

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?

With 9 parameters, no output schema, and no annotations, the description is far from complete. It addresses only the URL use case, leaving the purpose and behavior of the other eight parameters unexplained. An agent cannot reliably call this tool for any input other than a simple URL without additional external knowledge.

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 coverage is 100% – every parameter has a description in the schema. However, the tool description adds no value beyond the schema; it only mentions URL normalization, while the schema lists many parameters unrelated to URLs. The description fails to clarify which parameters are relevant to the stated purpose or how the others interact, so an agent cannot determine what to pass for a non-URL request.

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 action and result: 'Return origin, host, and path for a URL.' This clearly identifies the tool's primary function and distinguishes it from sibling tools like domain-shape or browser-url-ok, which focus on validation rather than normalization. However, the input schema includes many unrelated parameters (city, feed, json, zone, etc.), suggesting the tool may serve additional purposes not reflected in the description, which slightly muddies the overall purpose.

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 specific conditions, exclusions, or sibling tools that might be preferred for certain tasks. An agent is left to infer that this is for URL normalization, but with 28 sibling tools, explicit routing would be helpful.

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