list_timezones

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

No annotations are provided, so the description carries full burden. It states it returns 'all valid IANA timezone identifiers' and mentions optional filters, but lacks details on rate limits, auth, or potential side effects. The return type is mentioned but not detailed.

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 concise with a few sentences and a clear bullet-like list for parameters. Every sentence adds value, and there is no redundant information.

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?

For a simple tool with two optional parameters and no output schema, the description covers purpose, filtering, and return type. It could mention that no filters return all timezones, but it is still fairly complete.

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?

Input schema has 0% description coverage, but the description's Args section adds meaning: country_code is 'optional ISO 3166 country code filter' and search is 'optional substring search filter (case-insensitive).' This compensates well, though format details for country_code are absent.

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 'List available IANA timezones with optional filtering,' using a specific verb and resource. It distinguishes itself from sibling tools like get_local_time or convert_time by focusing on listing identifiers rather than getting times.

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?

It explicitly says 'Helps discover correct timezone names and prevents hallucination of invalid timezones,' indicating when to use it. However, it does not mention when not to use or provide explicit alternatives, though sibling tools are different in purpose.

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