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

With no annotations provided, the description carries the full burden of behavioral disclosure. It explicitly states that query and fragment are dropped, which is a key behavioral trait. However, it does not mention error handling for invalid URLs, what happens if the input is not a valid URL, or whether the operation is side-effect free. Given the simplicity, the description covers the main behavior but leaves some gaps.

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 extremely concise, consisting of two short sentences. The main purpose is front-loaded, and there is no unnecessary verbiage. Every word contributes to understanding what the tool does.

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 insufficient for the tool's complexity. Although the schema has 9 parameters, the description only addresses URL normalization and says nothing about the other parameters (ref, city, feed, host, json, path, zone, query). It is unclear whether these are ignored or used in some way. An agent cannot fully understand how to call this tool correctly, especially since the schema's parameters seem unrelated to the described behavior. The description should clarify that only the 'url' parameter is used, or explain how the others factor in.

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 has 100% description coverage for its 9 parameters, so the baseline is 3. The tool description does not add additional meaning to any parameter; it only mentions the URL concept, while the schema includes unrelated parameters like city, json, and zone. The description does not clarify how these parameters are used, but since the schema already describes them, the description does not need to repeat that. It provides marginal value 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 clearly states the tool's function: 'Return origin, host, and path for a URL. Query and fragment are dropped.' This uses a specific verb (Return) and resource (URL), and the behavior distinguishes it from siblings like browser-url-ok (which checks availability) and domain-shape (which validates shape). The purpose is unambiguous and non-tautological.

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 implies usage for normalizing URLs, but it does not explicitly state when to use this tool versus alternatives such as domain-shape or figma-url-shape. It also does not mention any exclusions or prerequisites (e.g., whether the URL must be valid). The guidance is adequate but relies on the agent inferring the tool's role from its name and description.

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