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

With no annotations provided, the description transparently frames this as a read-only lookup of current time, implying no side effects. It does not discuss error behavior or ignored parameters, but for a simple time lookup this is adequate.

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, compact sentence with no filler or redundancy. It is front-loaded and directly states the tool's purpose.

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 description is complete enough for a simple tool with no output schema, as it names the requested input and result. It could be more explicit about return format, but that is not essential for correct invocation.

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 already provides full coverage: the relevant 'zone' parameter is documented as 'IANA timezone name' and all other parameters carry 'discarded' descriptions. The tool description adds little semantic information beyond restating that the zone is an IANA timezone.

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 is a clear, specific statement of function: it returns the current time for a user-supplied IANA timezone. This distinguishes it from siblings like utc-time or iana-zones by the explicit IANA naming requirement.

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 phrase 'named IANA timezone' clearly conveys when the tool is appropriate—when a caller needs current local time in a specific IANA zone. It does not explicitly reference sibling alternatives, but the context is sufficiently clear for tool selection.

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