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

The description transparently states that query and fragment are dropped and that the output includes origin, host, and path. However, it does not disclose error behavior, side effects, or handling of invalid URLs, and there are no annotations to fill that gap.

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 and front-loaded, stating the action and primary output in the first sentence. It is appropriately sized, though it could benefit from a brief note about which parameter is required.

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 no output schema and no explicit statement that only the 'url' parameter should be used, the tool definition leaves important context ambiguous. The description says what is returned but not in what shape, and the extra schema parameters are not addressed.

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 includes nine optional parameters, but only 'url' is relevant to the description. The other parameters have unrelated, copied-sounding descriptions such as 'Git ref name; discarded after the shape check' and 'City name for a public weather hint', which are confusing and misleading in context.

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 returns origin, host, and path for a URL and explicitly says query and fragment are dropped. This gives a specific verb, resource, and output behavior, though it omits details about normalization beyond that.

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 does not explain when to use this tool versus the many sibling tools such as browser-url-ok, fetch-status, or web-fetch. It also gives no guidance about acceptable input URL formats or expected output structure.

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