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

With no annotations, the description carries the full behavioral burden. It does say the tool returns components and drops query/fragment, which implies a read-only transformation, but it does not describe malformed URL handling, whether unrelated parameters are ignored, or whether any network/disk access occurs.

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 only two sentences, with no filler and the core purpose front-loaded. Each sentence contributes to understanding the tool's behavior.

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 tool with 9 optional parameters, no annotations, and no output schema, two sentences are not enough. The agent cannot confidently determine which parameter to populate or what happens when the input is not a URL, making safe 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?

Schema description coverage is 100%, so the baseline is 3. The description adds little beyond the schema and fails to identify which optional parameter should actually be treated as the URL input, leaving real ambiguity across the 9 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 uses a specific verb and resource: 'Return origin, host, and path for a URL' and adds a key behavioral detail ('Query and fragment are dropped'). It is clear, but it does not explicitly differentiate itself from sibling URL-related tools such as domain-shape or browser-url-ok.

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 guidance on when to use this tool versus sibling tools, and no prerequites or exclusions. The only contextual hint is the phrase 'for a URL', which is too weak given that the schema has 9 optional fields and 0 required fields.

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