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

The description reveals only the output (a UTC timestamp) but nothing about the tool's behavior, such as whether it accepts optional parameters, how it handles the provided schema fields (url, host, json, zone), or any side effects. No annotations are provided, so the description carries the full burden of disclosure, which it does not meet.

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, consisting of a single short sentence that directly states the primary output. It is front-loaded and avoids unnecessary words. However, it omits any mention of the parameters or usage context, which detracts from its overall effectiveness but does not inflate its length.

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?

Given the tool's apparent simplicity, the description is too terse. It fails to explain the purpose of the four schema parameters, any optional behavior, or how this tool relates to the sibling tools. There is no output schema, and the description does not provide enough context for an agent to correctly invoke the tool beyond a trivial call with no 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?

The schema defines four parameters (url, host, json, zone) with descriptions, but these are completely unrelated to a tool returning a current UTC timestamp. The parameter descriptions (e.g., 'HTTPS URL to normalize or cite') appear to be copy-pasted from other tools and provide no meaningful semantics for this tool. The description does not explain how or whether these parameters affect the output.

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 the tool's output, which is a current UTC timestamp. It is implicitly distinct from sibling tools like timezone and iana-zones, which deal with timezone conversions and lists. However, it lacks a verb form and does not explicitly differentiate from 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?

No guidance is provided on when to use this tool versus the sibling tools such as timezone or iana-zones. The description does not mention any conditions, alternatives, or context in which this tool should be preferred.

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