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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states the basic action, but does not disclose whether the tool makes a network request, what format the returned time is in, how it handles invalid zone names, or that the other eight parameters in the schema are effectively ignored. The single sentence offers minimal transparency beyond the stated action.

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, front-loaded sentence that is concise and free of filler. However, given the tool's 9-parameter schema and lack of annotations, the description is likely underspecified rather than adequately sized; it could benefit from a second sentence clarifying which parameter to use or the return format.

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 9 parameters, no output schema, and no annotations, and the description is a single line. It does not explain what is returned (e.g., time format, timezone, UTC offset), what happens when the zone parameter is omitted (it is not required), or what the 'discarded' parameters mean for behavior. The agent is left to guess at the invocation pattern and result structure.

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 coverage is 100%, so the baseline is 3. The description mentions a 'named IANA timezone,' which loosely aligns with the zone parameter, but it does not add meaning beyond the schema descriptions. It does not clarify that zone is the effective parameter or that the other eight parameters are irrelevant for this tool's purpose, though the schema already describes them as 'discarded.'

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 the tool's purpose clearly: it returns the 'current time' for a 'named IANA timezone.' This is a specific verb+resource that separates it from sibling tools like utc-time and iana-zones, though it does not explicitly name those alternatives.

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, when not to use it, or how it differs from closely related siblings such as utc-time or iana-zones. There are no exclusions, prerequisites, or example scenarios, leaving the agent to infer the intended context.

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