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 disclose the key behavior of dropping query and fragment, which is useful. However, the schema lists nine optional parameters with descriptions unrelated to URL normalization (e.g., 'city', 'feed', 'zone'), and the description does not clarify that only the 'url' parameter is actually used or that all others are ignored. This discrepancy between the description's narrow scope and the schema's broad surface creates confusion rather than transparency.

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, efficient sentence that front-loads the primary output and the dropping behavior. It wastes no words. However, it could have briefly noted that only the 'url' parameter matters, which would have improved clarity without adding much length. Still, it is appropriately concise.

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's complexity (a simple URL normalization) and lack of output schema, the description is mostly adequate for the core behavior. But the schema's nine optional parameters with unrelated meanings are not explained, and the description does not indicate that most are ignored. This is a significant completeness gap: an agent could reasonably assume the tool accepts and uses multiple inputs. There is also no mention of return format beyond 'origin, host, path' or error behavior for invalid URLs.

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 all parameters are documented in the schema. The description adds no additional parameter semantics; it only mentions 'a URL' without specifying which parameter. Since the schema already covers each parameter, the baseline of 3 applies. The description does not compensate for the schema's irrelevant parameters, but it does not need to given high coverage.

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 tool's function: 'Return origin, host, and path for a URL. Query and fragment are dropped.' This is a specific verb-resource pair and distinguishes it from siblings like fetch-status or validate-json. However, it does not explicitly name alternative tools or edge cases that separate it from similar URL-handling tools such as browser-url-ok, so it stops short of 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?

No guidance is given on when to use this tool versus any of the 25 siblings. The description does not mention scenarios where normalization is preferred over other URL-checking tools, nor does it state any prerequisites or typical use cases. This leaves the agent to infer the appropriate context.

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