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

No annotations are provided, and the description does not disclose any potential side effects, permissions, or whether it performs any actions beyond returning a timestamp. It is a simple getter, but the lack of any explicit transparency note limits the score.

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 that gets to the point immediately. It is well-structured for brevity, though it sacrifices necessary detail, which prevents a perfect score.

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?

The description is far too incomplete for the tool's complexity. It does not explain the role of the four parameters, the output format, or how this tool fits among siblings. Essential context is missing, leaving the agent unable to use it correctly.

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 schema lists four parameters (url, host, json, zone) with full descriptions, but none of these are logically related to fetching a UTC timestamp. The tool description does not explain how these parameters are used, creating a severe mismatch between the tool's purpose and its input 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 states the tool returns the current UTC timestamp, which is clear in intent. However, it lacks details about the output format or how it differs from sibling tools like tz-utc or timezone, making it ambiguous in a broader context.

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 provides no context, use cases, or conditions, leaving the agent to guess when this should be invoked.

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