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

With no annotations, the description must disclose behavior itself, but it only states the basic result. It doesn't say whether the call is read-only, what happens for invalid or missing timezone names, whether extra parameters are ignored, or what format the time is returned in.

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?

A single sentence with no filler; it front-loads the essential idea and doesn't repeat the tool name. It is highly scannable and concise.

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?

There is no output schema and no annotations, but the description never explains the return value, error behavior, or the relevance of the many unrelated-looking schema fields. An agent selecting parameters for a lookup gets only the timezone hint and no guidance on required inputs.

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 covers all 9 parameters at 100%, so the baseline applies. The description loosely matches the timezone parameter ('IANA timezone name') but adds no meaning about the other parameters or how to use them.

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 that the tool gives the current time for a named IANA timezone, which is specific enough to distinguish it from list-like siblings such as iana-zones. It lacks an explicit verb and doesn't mention output format, so it stops short of full clarity.

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 use case is implied: call it when you need the current time in a specific IANA timezone. It doesn't explicitly point to alternatives like utc-time for UTC or iana-zones for zone lists, and gives no when-not-to-use guidance.

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