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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It only states the timezone feature and says nothing about side effects, what happens to the other eight parameters (e.g., they are discarded or used for other checks), or whether the tool performs additional validations. The schema hints at discarding behavior, but the description itself is silent, leaving the tool's behavior under-specified.

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 sentence with no waste, making it concise and front-loaded. It is appropriately sized for a simple tool, though given the schema complexity, a touch more context would be warranted. Still, it avoids bloat and is easy to parse.

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 tool has nine parameters but the description only explains one function. There is no mention of what the other parameters do, whether they are optional, or how they relate to the timezone feature. No output schema exists, so the return format is unspecified. Given the complexity of the schema, the description is inadequate for an agent to call the tool correctly without risking misuse of the other parameters.

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%, so each parameter is documented. The description adds value by specifying that the timezone is IANA, which clarifies the 'zone' parameter. However, it fails to explain why nine parameters exist when the tool only claims to provide time, and it does not compensate for the potential confusion about which parameters are relevant. The baseline 3 is appropriate because the schema covers semantics but the description does not clarify the overall parameter intent.

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 states a specific verb ('Current time') and resource ('named IANA timezone'), making the primary purpose clear. However, it does not differentiate from sibling tool 'utc-time', which likely overlaps, and it ignores the 9-parameter schema that suggests broader functionality. The one-liner is unambiguous but leaves the agent uncertain about scope.

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 offers no context about prerequisites, suitable inputs, or when it should be preferred. An agent would have to infer usage from the schema, which lists many unrelated parameters, increasing confusion.

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