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

With no annotations, the description carries the transparency burden. It discloses the core transformation—returns origin/host/path and drops query/fragment—but it does not mention whether the tool makes network requests, how invalid URLs are handled, or that non-url parameters are ignored. Adequate but not detailed.

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 sentences, front-loaded with the action and output, and no filler. Every word earns its place.

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 9-parameter tool with no output schema and no annotations, the description is under-specified. It does not explicitly identify `url` as the sole meaningful input—some params like `host` and `path` are not labeled as discarded—and it does not describe the return structure or edge-case behavior.

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%, so the baseline is 3; the description adds the useful fact that URL query and fragment are dropped. However, it introduces some ambiguity by not stating that only `url` matters while eight other parameters are accepted, and 'query' could be confused with the URL query component.

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?

States a specific verb ('Return') and resource ('URL'), and names the exact output fields (origin, host, path). This distinguishes it from siblings that check or fetch URLs, such as browser-url-ok or 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?

No when-to-use or when-not-to-use guidance is provided, and no alternatives are named. The agent must infer from the output fields that this is for extracting URL components, with no explicit context versus validation, fetching, or other URL-related tools.

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