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

With no annotations supplied, the description carries the behavioral disclosure burden. It does add a useful behavioral trait ('Query and fragment are dropped') beyond the name, but it does not disclose output format, error behavior for invalid URLs, whether the URL is actually fetched, or what happens with non-URL inputs.

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 with the main action first and the filtering behavior second. Every word earns its place and no irrelevant detail is included.

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?

Despite high schema coverage, the definition is incomplete for a tool with nine optional parameters and no output schema. The agent is not told that `url` is the effective input, whether other parameters are ignored, or what the returned origin/host/path value looks like, making correct invocation uncertain.

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?

Input schema descriptions cover 100% of the nine parameters, so the baseline is 3. The tool description adds only marginal meaning by clarifying that `url` produces origin/host/path with query and fragment removed; it does not clarify the confusing role of the eight auxiliary parameters.

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 names a concrete operation ('Return origin, host, and path for a URL') and specifies what is excluded ('Query and fragment are dropped'), which is enough to identify the tool's purpose. It does not explicitly compare against sibling URL tools such as browser-url-ok or fetch-status, and the phrase 'origin, host' is slightly redundant, so it stops short of a perfect 5.

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?

There is no statement about when to use this tool versus alternatives, nor any warning about when not to use it. The schema has nine optional parameters, but the description never points to `url` as the relevant input or tells the agent that the other fields are validation-only or ignored.

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