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

No annotations are provided, so the description must fully disclose behavior. It only states 'Current time' implying a read-only operation, but does not mention that the schema includes many irrelevant parameters that are discarded or ignored. This omission is a significant behavioral gap that could confuse an agent into thinking other parameters matter.

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, efficient sentence that is front-loaded with the core action. It contains no fluff, but also omits necessary clarifying details about the parameters and scope.

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 complexity of the schema (9 params, only 1 relevant), the description is incomplete. It does not specify the output format, mention that only 'zone' is used, or explain the behavior of the other parameters. Without an output schema, the agent has no idea what to expect in return, and the presence of irrelevant params makes correct invocation ambiguous.

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?

While schema description coverage is 100%, the tool description adds no clarification about which parameter (zone) is the operative one. The schema itself includes nine parameters, many of which appear unrelated to timezone lookup (e.g., 'ref', 'url', 'city'), and the descriptions for those indicate they are discarded, but the tool description fails to highlight that only 'zone' is relevant. This leaves the agent uncertain about how to use the tool correctly.

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 returns the current time for a named IANA timezone, which is a specific verb-resource combination. It is distinguishable from siblings like 'utc-time' and 'iana-zones' in that it returns a time for a specific named zone, but it does not explicitly name those alternatives or contrast itself.

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 on when to use this tool versus alternatives like 'utc-time' or 'iana-zones'. The description does not mention conditions, exclusions, or preferred usage contexts. An agent must infer when to pick this over a sibling.

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