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

No annotations are provided, so the description carries the full behavioral disclosure burden. It only says 'Current UTC timestamp' and does not mention output format, side effects, or the fact that all provided parameters are discarded/ignored, which is important given the unusual input 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 a single concise sentence with no filler or repetition. It is front-loaded and easy to parse, though its brevity leaves out behavioral and usage details that would make it fully effective.

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 tool has nine optional parameters, no output schema, and no annotations, yet the description only provides a bare phrase. It does not explain what the returned timestamp looks like, why the parameters exist, or whether they should be supplied at all, so the description is not complete enough for confident invocation.

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%, and each parameter already has a description, including notes like 'discarded after the call'. The tool description adds no parameter-level meaning, but the schema already handles parameter documentation, so the baseline of 3 is appropriate.

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 a clear, specific outcome. It distinguishes the tool from siblings like 'timezone' and 'iana-zones' by naming UTC time specifically, though it does not explicitly name alternatives.

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 gives no guidance on when to use this tool versus sibling tools such as 'timezone' or 'iana-zones'. It also does not clarify that all nine input parameters are optional and effectively irrelevant, leaving the agent to infer calling conventions from the schema.

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