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

With no annotations, the description carries the full burden of behavioral disclosure, but it only states the core function. It does not describe the output format, whether it accepts abbreviations, what happens for invalid zone names, or any side effects (even though a read is implied).

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 7-word sentence with no filler. Every word earns its place, and the core idea is front-loaded.

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?

For a simple time lookup the description is nearly sufficient, but the absence of any output schema or annotations, combined with the schema's unrelated parameters, leaves important gaps. An agent cannot tell what the response looks like or how to handle invalid input.

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% for all four parameters, including 'zone' with 'IANA timezone name'. However, the schema also includes url, host, and json parameters that appear unrelated to a timezone lookup, which could confuse an agent. The description adds no extra meaning beyond what the schema already provides.

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 'Current time in a named IANA timezone' uses an implied verb with a clear resource and scope. It is specific enough to differentiate from the siblings, which all concern URLs, citations, or JSON rather than time.

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?

No guidance is given about when to use this tool versus alternatives, and no sibling is mentioned as an alternative or exclusion. The description only states what it does, not when it should be selected.

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