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. It fails to mention that only the 'zone' parameter is used and that all other parameters are ignored, nor does it describe the output format (e.g., string, ISO timestamp). This is a significant gap for an agent deciding whether to call it.

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 wasted words, which is efficient. However, given the complexity of the schema (9 parameters), it is under-specified and omits crucial clarification about parameter usage. It is concise but at the expense of necessary detail.

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, most of which appear unrelated to timezones (e.g., ref, url, city, feed), and no output schema. The description does not explain the role of these parameters or the return value, leaving agents without enough context to call it correctly.

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 schema already describes each parameter with 100% coverage, so the baseline is 3. The description adds no additional parameter meaning and does not clarify which parameters are actually used or required. It neither improves nor detracts from the schema's own descriptions.

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 specified IANA timezone. It distinguishes from siblings like utc-time (UTC) and iana-zones (list zones) by focusing on a named zone. However, it does not mention that the other parameters in the schema are irrelevant, which slightly muddies the 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?

No guidance is provided on when to use this tool versus alternatives such as utc-time for UTC or iana-zones for listing zones. The description simply states functionality without any usage context or exclusions.

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