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

With no annotations provided, the description carries the behavioral disclosure burden. It adequately discloses the dynamic nature of the result (current time), the format (ISO 8601), and the timezone (UTC). No hidden mutation or side effect is implied or omitted for a zero-parameter read-only tool.

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?

A single tightly worded sentence conveys the operation, resource, format, and timezone with no wasted words. All essential information is front-loaded.

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?

For a no-parameter, no-output-schema tool of minimal complexity, the description fully covers what an agent needs to know: what is returned and in what format/timezone. Nothing important is missing.

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 tool has zero parameters, so there is no parameter complexity for the description to clarify. The baseline of 4 applies; the description appropriately focuses on the return value rather than adding meaningless parameter details.

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?

States a specific verb ('Returns'), a precise resource ('current server time'), and specifies format and timezone ('ISO 8601, UTC'). This fully distinguishes it from sibling tools like add and echo, whose purposes are unrelated.

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 makes the tool's purpose clear enough that an agent can infer when to use it: whenever the current server time is needed. It does not explicitly discuss alternatives, but the sibling tools are clearly unrelated and there is no ambiguity about selecting this tool.

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