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

With no annotations, the description must carry the full behavioral burden. It does disclose a key behavior: 'Query and fragment are dropped.' This is useful. However, it says nothing about what happens to the other eight parameters (e.g., city, ref, json) that appear in the schema, leaving the agent to wonder whether they are ignored, cause errors, or alter behavior. The description is minimal and does not address error handling, side effects, or permission needs.

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 states the core output and a key constraint. It is front-loaded with the main action. However, it omits essential context about the other parameters, so while concise, it is under-specified. Length is appropriate, but structure could include more guidance.

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 and no output schema, the description is far from complete. It explains only the URL normalization aspect and ignores the other parameters entirely. An agent cannot fully understand the tool's behavior without exploring the schema, which includes fields like 'city' and 'json' that seem unrelated. The description does not explain whether these are ignored or trigger different behavior, making it inadequate for a tool with this complexity.

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 schema already documents all parameters. The tool description adds no additional parameter-specific detail beyond the core 'url' handling. Since the schema covers everything, the baseline of 3 applies. The description does not clarify the relationship between the many unrelated parameters and the normalization function, but it also does not contradict the schema.

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 primary function: 'Return origin, host, and path for a URL.' This is a specific verb and resource. However, it does not mention the many other parameters in the schema, which could confuse an agent about the tool's actual scope. It doesn't explicitly differentiate from siblings like browser-url-ok or fetch-status, but the core purpose is unambiguous.

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 the many sibling tools. The description does not mention any conditions, prerequisites, or alternatives. An agent cannot determine whether normalize-url is better than browser-url-ok or github-repo-shape for a given task. No exclusionary or contextual information is provided.

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