timezone_info

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

With no annotations provided, the description carries the behavioral disclosure burden. It discloses determinism, reliance on the IANA database, and correct handling of zones without DST, which are meaningful behavioral traits. It does not state invalid-timezone behavior or return formatting, but the disclosed traits go well beyond a bare 'get timezone information' statement.

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?

Three short sentences with no redundant wording. The main purpose and output list are front-loaded, followed by a supporting detail (IANA) and an edge-case guarantee, all of which earn their place.

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 two-parameter query tool with no output schema, the description covers the key behavioral surfaces: what is returned, the underlying database, and a known edge case. It would be slightly more complete with explicit error behavior for invalid timezone strings, but the essentials for correct invocation are present.

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 the schema already documents both parameters. The description adds a little context by mentioning IANA and DST transitions, but it does not materially elaborate on the reference_time parameter or provide format/validation details beyond the schema.

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 uses a specific verb ('Get') and names an exact resource ('timezone information') followed by a concrete list of outputs: UTC offset, DST status, abbreviation, and next/previous DST transitions. This clearly differentiates it from sibling tools like now or convert_time, which focus on current time or conversion rather than timezone metadata.

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 implies usage through its emphasis on DST transitions, IANA timezone data, and no-DST correctness, but it never explicitly states when an agent should choose this tool over alternatives such as convert_time or resolve_time. It also does not mention exclusions or when to avoid the tool.

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