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

With no annotations, the description must carry the full behavioral burden, but it only states the output. It does not disclose that the many input parameters are effectively ignored or that they do not affect the returned timestamp, leaving significant ambiguity.

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?

'Current UTC timestamp.' is extremely concise and front-loaded, with no wasted words. However, it is so brief that it omits important context about the input schema, making it concise at the cost of completeness.

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 incomplete for a tool with 9 unrelated optional parameters and no output schema. It should explicitly state that parameters are accepted but ignored, and that the result is always the current UTC time, to prevent an agent from passing context-dependent arguments.

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 individual parameter descriptions already document side effects such as 'discarded after the shape check' and 'no disk access.' The tool description adds nothing about parameters, but the schema carries that weight, 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 clearly identifies the resource and result: 'Current UTC timestamp.' It is specific about UTC, which helps distinguish it from the 'timezone' sibling, but it lacks an explicit verb and does not acknowledge the unusual 9-parameter input schema.

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 usage guidance is provided. The description does not say when to use this tool instead of siblings like 'timezone' or 'iana-zones', nor does it clarify that all parameters are optional and apparently ignored.

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