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

The description offers minimal behavioral detail beyond the tool name. It does not specify output format, timezone handling, or precision, and annotations are absent. For a tool that simply returns the current UTC timestamp, more detail on the format would improve 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 one sentence and is appropriately short. It says exactly what it needs to without any fluff. However, the ultra-brief style leaves no room for necessary details in other dimensions.

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 lacks details about the output format, timezone behavior, or parameter usage. Although it's a simple tool, an agent might need to know the format of the timestamp. This makes it insufficient for complete context.

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 description does not explain any parameters, despite there being 4 parameters in the schema. The schema descriptions are 100% covered, but the description itself adds no value toward parameter understanding. The parameters seem unrelated to simply getting a UTC timestamp, creating potential confusion for an agent.

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 is simple and clear but slightly vague on purpose. It explicitly identifies the action and resource (return current UTC timestamp), but it is too short to distinguish from possible sibling tools that might also return time-related information.

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 compared to alternatives. No mention of contexts, limitations, or explicit exclusions. However, the tool name and description make the usage fairly obvious for a simple time tool.

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