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

With no annotations provided, the description carries the full burden. It does not disclose that all input parameters appear to be ignored or discarded, which is a notable behavioral gap given the nine optional parameters in the schema.

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 concise at four words, which is appropriate for a trivial utility. While short, it still communicates the core purpose effectively without unnecessary filler.

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 omits essential context: it does not mention that the parameters are ignored, does not specify the return format (e.g., ISO 8601), and provides no indication of whether the tool is read-only or side-effect-free. Given the confusing parameter list, the description is not complete enough for an agent to use confidently.

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 includes nine optional parameters whose descriptions indicate they are 'discarded' or irrelevant to the tool's purpose, but the description does not explain why they exist or how they relate to 'utc-time'. This leaves the parameter list confusing and effectively meaningless for this tool.

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 what the tool returns, which is sufficient for a simple time utility. It is less explicit than a verb-driven phrase, but it distinguishes the tool from timezone-related siblings like 'timezone' and 'iana-zones'.

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 about when to use this tool instead of alternatives such as 'timezone' or 'iana-zones'. The description implies a simple current-time use case, but it does not explicitly state conditions or exclusions.

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