lookup_timezone

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

With no annotations, the description carries the full burden. It indicates a read-only lookup but does not disclose behavior for ambiguous names, multiple matching timezones, or error handling. It does provide an example and notes that results are IANA timezone(s), adding some context.

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 two sentences, front-loaded with the primary action and example, and has no filler. Every sentence adds value, making it highly concise and well-structured.

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 simple nature (1 param, no output schema), the description is mostly complete: it states purpose, usage context, and example. However, it does not specify whether output is a string or array when multiple timezones match, nor how failures are handled, leaving minor 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 schema already provides 100% coverage of the single parameter 'city_or_country' with a clear description. The main description only adds an example ('Delhi'), which is helpful but not substantial beyond the schema definition.

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 resolves a city or country name to IANA timezone(s), using a specific verb 'Resolve' and a concrete example ('Delhi' -> 'Asia/Kolkata'). This distinguishes it from sibling tools that likely require exact timezone identifiers.

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 explicitly says 'Use it first when you only have a place name,' providing clear guidance on when to use this tool. It also implies the alternative (knowing the exact identifier) by saying 'so you don't need the exact identifier.'

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