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

The description discloses a valuable behavior beyond any annotations: query and fragment are dropped, which reveals the normalization transformation. However, with no annotations to carry the safety or side-effect burden, it fails to disclose what happens when the other schema parameters (host, json, zone) are supplied, and it implicitly conflicts with the schema by listing host as an output while the schema accepts it as an input.

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 with no filler. The primary outcome is front-loaded ('Return origin, host, and path'), and the second sentence adds the crucial transformation detail about dropped query and fragment. Every sentence 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?

The tool has 4 optional parameters and no output schema, yet the description only covers the URL case. It never explains why host, json, and zone are accepted as inputs, whether url is actually required, or what happens when multiple parameters are passed together. An agent cannot confidently predict the tool's behavior for any invocation other than a simple url-only call.

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 no per-parameter semantics beyond the schema; it only implies that url is the primary input and that origin, host, and path are the output components. It does not clarify the oddity of host, json, and zone being optional inputs at all.

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 states a concrete operation: 'Return origin, host, and path for a URL' and adds a specific behavior note that query and fragment are dropped. The verb and resource are clear. However, it does not differentiate from sibling tools, and the schema's unrelated optional parameters (host as input, json, zone) muddy the tool's true scope, so it doesn't earn a 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 guidance on when to use this tool versus alternatives, no prerequisites, and no clarification that url is effectively required despite the schema having 0 required parameters. The description implies usage through its return statement, but the mix of url, host, json, and zone parameters leaves an agent without a clear decision rule for calling the tool.

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