time.get_current

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

With no annotations, the description carries the burden of behavioral disclosure. It explains the timezone format and default, implying a read-only operation. However, it doesn't explicitly state that the operation has no side effects or mention error handling for invalid timezones, leaving a slight gap. The nature of the tool (getting current time) makes this less critical.

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 two sentences long, with no unnecessary words. It front-loads the core purpose, then adds usage guidelines and parameter details in a logical order. Every sentence earns its place.

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 simplicity of the tool (one optional parameter), the description is complete. The output schema exists to describe the return value, so the description needn't elaborate. It covers when to use, how to use, and the default behavior thoroughly.

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 provides just the parameter name and default. The description adds crucial semantics: it explains what IANA names are, gives an example, and clarifies the default as Beijing time. This fully compensates for the zero schema coverage.

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 function with a specific verb ('获取') and resource ('指定时区的当前日期和时间'), distinguishing it from the sibling calculator tool. It also provides usage context, making the purpose unambiguous.

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 explicitly tells when to use the tool ('当用户询问现在几点、今天日期或星期时调用'), and even specifies the parameter format and default behavior. This is clear guidance with no alternative tools mentioned, but that's fine because the sibling is unrelated.

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