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

With no annotations, the description carries the full burden of behavioral disclosure. It does state that query and fragment are dropped, which is a specific behavioral trait. However, it fails to explain what happens to the many other accepted parameters (ref, city, feed, host, json, path, zone, query) – they are silently discarded after a shape check or similar, as hinted by schema descriptions, but the tool description gives no clue. This is a significant gap for a tool that appears polymorphic but is described as a simple URL normalizer.

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, concise sentence with no fluff. It front-loads the primary action and output. However, it is under-specified given the schema complexity, but that is more a completeness issue than a conciseness issue. For conciseness alone, it earns a 4.

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 9 optional parameters, no output schema, and no annotations, the description is severely incomplete. It does not explain what the output format looks like (even though it says 'return origin, host, and path', it doesn't specify whether it's a JSON object, string, etc.), nor does it clarify the role of the other 8 parameters. An agent cannot reliably call this tool correctly based on the description alone.

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 baseline is 3. However, the tool description adds no meaning beyond the schema: it only mentions 'URL' behavior, while the schema lists 9 parameters, many of which (city, feed, json, zone, etc.) seem irrelevant to the stated purpose. The description does not clarify which parameters are relevant or how they interact. This fails to compensate for the schema's generic descriptions and leaves an agent uncertain about what to pass.

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 specific verb+resource: 'Return origin, host, and path for a URL.' It clearly defines the tool's primary action and output. However, it does not mention the 8 additional parameters in the schema, and it does not differentiate from sibling tools like browser-url-ok or figma-url-shape, which likely share similar URL-shape purposes. The core purpose is clear but the scope is not fully bounded.

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. The description does not mention any exclusions, prerequisites, or context for choosing normalize-url over siblings like browser-url-ok or figma-url-shape. An agent receives no direction on selection.

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