Get the exact UTC offset of an IANA timezone at a given instant, DST-aware. Correctly handles fractional offsets such as India +05:30 and Nepal +05:45.
| Name | Required | Description | Default |
|---|---|---|---|
| instant | No | ISO 8601 or natural language. Defaults to now. | |
| timezone | Yes | IANA timezone. |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries full burden. It discloses DST awareness and fractional offset handling, adding value beyond the schema. However, it omits details on error handling, return format, or behavior with invalid inputs, limiting transparency.
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?
Two concise sentences: first states core purpose and behavior, second highlights an important edge case. No redundant words; each sentence earns its 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?
No output schema is provided, so the description should clarify return values. It implies the offset format via examples but does not explicitly state it. Parameter coverage is good, but missing error behavior or return format details make it slightly incomplete for a tool with no annotations or output schema.
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 baseline is 3. The description adds context by mentioning DST awareness (relating to instant) and fractional offsets (relating to timezone), providing some additional meaning beyond the parameter 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 gets the exact UTC offset of an IANA timezone at an instant, DST-aware. It distinguishes from sibling tools like convert_timezone or list_timezones by focusing on offset retrieval, and includes specific examples of fractional offsets.
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 for getting UTC offsets but does not explicitly provide guidance on when to use this tool versus alternatives like convert_timezone, or any exclusions. No when-not or alternative references are given.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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Each tool has a clearly distinct purpose: conversion (single and batch), arithmetic, meeting scheduling, holiday checking, timezone lookup, current time, and offset. No two tools overlap in functionality.
All tool names follow a consistent verb_noun pattern using snake_case (e.g., convert_batch, list_timezones, is_holiday). Minor variations like 'now_in' and 'tz_offset' still adhere to the pattern.
Nine tools is ideal for a timezone toolkit. Each tool serves a distinct and necessary function without being excessive or insufficient for the domain's scope.
The toolset covers all major timezone operations: conversion, arithmetic, current time, offset, discovery, holidays, and meeting slot calculation. No obvious gaps for common use cases.