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

With no annotations present, the description carries the full burden of behavioral disclosure, but it only states the output without mentioning side effects, parameter handling, or return format. The schema separately notes that parameters are 'discarded' or entail 'no disk access,' yet the description itself adds no such 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 a single short phrase with no filler and front-loads the core output. For a tool that primarily returns a timestamp, this is appropriately sized and concise.

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 important contextual details such as the exact return format (e.g., ISO 8601 string vs. Unix epoch) and the fact that all accepted parameters are ignored. Given the unusual seven-parameter schema, an agent reading only the description could be misled about whether arguments affect the result, so the definition is not complete enough on its own.

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 input schema provides descriptions for all seven parameters, including explicit notes that values are discarded or not used for disk access, so schema coverage is high. The tool description itself adds no additional parameter meaning, which matches the baseline of 3 but does not improve it.

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 states the tool's output: the current UTC timestamp. However, it uses a noun phrase rather than an explicit verb+resource construction, and it does not differentiate itself from sibling tools like 'timezone' except through the word 'UTC'.

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 such as 'timezone' or other timestamp-related tools. The description also does not mention that all seven input parameters appear to be optional and are discarded, leaving the agent to infer the appropriate invocation context.

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