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

With no annotations, the description carries the full burden of disclosing behavior, yet it only says 'Current UTC timestamp.' It does not disclose side effects, statelessness, output format, or that the many input parameters are irrelevant to the result.

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 sentence with no filler, repetition, or marketing language. It is extremely compact and every word contributes to the intended meaning.

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 nine parameters, no output schema, and no annotations, the one-sentence description is under-specified. It leaves the return format, parameter role, and no-argument usage implicit, which is a meaningful gap for reliable tool selection.

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%, so the baseline is 3; every parameter already has its own meaningful description. The tool description itself adds no parameter-level meaning, but the schema compensates, including the repeated 'discarded' notices.

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 tool as returning the current UTC timestamp, so the primary purpose is not ambiguous. It does not use a specific verb and does not explicitly differentiate from sibling tools like timezone or iana-zones, but the core resource is evident.

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 provides no guidance on when to use this tool versus siblings such as timezone or iana-zones. It also does not state that the tool requires no parameters or what kinds of requests should be routed elsewhere.

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