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

No annotations are provided, and the description does not disclose any behavioral aspects such as read-only guarantees, side effects, or potential errors. The tool likely only performs a read, but this is not stated.

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 extremely concise and free of fluff, using a single sentence to convey the core function. There is no unnecessary detail or repetition.

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 read-only tool, the basic purpose is stated, but the description omits any details about output format, error handling, or constraints (e.g., what happens if the timezone name is invalid). Given the small scope, the missing information is minor but still leaves some gaps.

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 description mentions 'named IANA timezone' which clearly maps to the 'zone' parameter, but the schema includes eight other parameters with descriptions that seem unrelated to timezone lookup (e.g., 'Git ref name', 'HTTPS URL'). The tool description does not clarify that these parameters are irrelevant or that only 'zone' should be used, leaving ambiguity.

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: returning the current time for a named IANA timezone. However, it does not differentiate this from sibling tools like 'utc-time' or 'iana-zones' that might also deal with timezones, so it is not fully explicit about its unique purpose.

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 provides no guidance on when to use this tool versus alternatives. It only states what it does, lacking any contextual instructions such as 'use this for a specific timezone, use iana-zones for a list of zones'.

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