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

With no annotations provided, the description carries the full burden of disclosing behavioral traits. It only states the nominal function and fails to disclose potential side effects, permissions, or the fact that the parameters are unrelated to the stated purpose.

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 extremely brief ('Current UTC timestamp.'), which is concise but insufficiently informative. It avoids verbosity but omits critical details about parameters and usage, striking an unbalanced minimalism.

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 presence of four parameters, the description is severely incomplete. It does not explain what these parameters do, why they exist, or how they interact with the tool's core function, leaving the overall context utterly ambiguous.

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?

The parameter descriptions (e.g., 'HTTPS URL to normalize or cite') are entirely mismatched with the tool's stated purpose of returning a UTC timestamp. The tool description does not clarify how these parameters relate to its function, making them semantically meaningless in this context.

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 'Current UTC timestamp' clearly states the tool's purpose as returning the current UTC time. However, the presence of unrelated parameters (url, host, json, zone) introduces confusion about the actual functionality, preventing a perfect score.

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?

The description provides no guidance on when to use this tool versus alternatives (e.g., timezone, month-name). No conditions or edge cases are mentioned.

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