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

With no annotations, the description must carry the full burden of behavioral disclosure. It does state the main output (origin, host, path) and that query/fragment are dropped, which is useful. However, it fails to mention that the many auxiliary parameters (ref, city, feed, json, zone, query, etc.) are ignored or discarded, nor does it address error handling or invalid URL behavior. This is a significant gap.

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 a single, compact sentence that front-loads the primary outcome. It is efficient with no filler. However, it could be slightly more structured by naming the 'url' parameter explicitly, but overall it is concise and readable.

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 the tool has 9 parameters, no output schema, and a mix of irrelevant parameters in the schema, this description is inadequate. It does not clarify which parameter is the primary input, how the return value is formatted (string, object, etc.), or what happens with invalid URLs. The presence of many discarded parameters is not addressed, leaving the agent with significant ambiguity about correct invocation.

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% for all 9 parameters, so the schema already provides detailed descriptions for each. The tool description adds no parameter-level information beyond the schema. It does implicitly reference the 'url' parameter via 'for a URL', but does not elaborate on its format or constraints, leaving the schema to carry the semantic load as expected.

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 clearly states the verb ('Return') and resource ('origin, host, and path for a URL') and specifies that query and fragment are dropped, which distinguishes it from sibling URL tools like browser-url-ok or fetch-status. However, it does not explicitly name the 'url' parameter as the sole input, leaving ambiguity given the 9 unrelated parameters in the schema.

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 guidance is provided on when to use this tool instead of alternatives, nor any exclusion conditions. The description mentions only the operation, not the decision context. An agent gets no hints about prerequisites or when this tool is preferred over other URL-related siblings.

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