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

With no annotations, the description carries the burden and it does disclose a meaningful behavioral detail: the URL query and fragment are dropped. However, it does not mention that only the `url` parameter is used and the other eight parameters are decoys that will be ignored; this is left to individual parameter descriptions, creating potential ambiguity.

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?

Two-short sentences and every phrase is needed: the main output and the dropped components. No filler or redundancy.

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 a 9-parameter schema with numerous unsaturated optional params, no annotations, and no output schema, the definition is only minimally sufficient. It says what the tool returns but does not explain which parameters are actually relevant, nor account for the deceptive extra parameters, leaving the agent to puzzle through the schema descriptions to infer the right call shape.

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 already provides descriptions for all 9 parameters, so the baseline is 3. The description adds no direct parameter-level meaning except the ambiguous note that query and fragment are dropped, which may be confused with the `query` parameter. It does not clarify which field is the primary input beyond the schema's own wording.

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 uses a specific verb, 'Return', and a specific resource, 'URL', and clearly names the output components: 'origin, host, and path'. It also adds the key distinguishing behavior that query and fragment are dropped, which differentiates it from sibling URL-checking tools like browser-url-ok and web-fetch.

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 the tool is for extracting normalized URL components, but it does not explicitly state when to use it over related tools or provide exclusion criteria. With many URL-related siblings, the agent must infer the appropriate use rather than being given concrete routing guidance.

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