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

No annotations are provided, so the description carries the full burden for behavioral disclosure. The description states it 'gets' time and trading-day info, implying a read-only operation, but it does not disclose timezone specifics, the meaning of 'last trading day,' or any potential dependencies. This is acceptable for a trivial tool but lacks richer context.

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, front-loaded sentence with no filler. Every word contributes meaning, and the structure is clear and efficient.

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 tool is simple with no parameters, no output schema, and no annotations. The description lists the expected return values (ISO time, timestamp, last trading day), which is mostly complete, but it omits details like timezone or trading calendar context that could affect interpretation.

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 per the rubric the baseline is 4. The description adds no parameter-specific detail, but none is needed since the input schema is empty and there is nothing to clarify.

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 uses the specific verb 'get' with a clear resource ('current time') and explicitly lists the outputs: ISO format, timestamp, and last trading day. This distinguishes it from the many financial sibling tools, which focus on market data rather than time information.

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 clearly indicates the tool's context: use it when you need current time formatted as ISO, a timestamp, or the last trading day. It does not explicitly exclude alternatives or provide when-not-to-use guidance, but the zero-parameter nature and simple purpose make the intended usage evident.

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