datetime.tz_convert

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

Annotations already declare readOnly/idempotent/closed-world, and the description adds genuinely new behavioral rules beyond them: offset precedence (from_tz ignored when an offset is present) and DST-overlap disambiguation to the earlier instant. It stops short of stating error behavior for invalid IANA names, so not a 5.

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 tightly packed sentences: purpose first, then input format, then ambiguity rules. No filler, and the highest-risk detail (offset precedence) comes before the DST edge case.

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?

An output schema exists, so return values need not be described, and annotations cover safety. Combined with the input-format and DST rules the definition is nearly sufficient; only failure modes (unknown timezone, unparseable datetime) are unaddressed.

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 0%, so the description must carry the parameter burden and largely does: iso_datetime format is spelled out (YYYY-MM-DDTHH:MM:SS, space allowed, no fractional seconds) and from_tz's conditional use is defined. to_tz is only implicitly covered — the reader must infer it drives the output offset.

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?

States a specific verb and resource ('IANA 타임존 사이에서 시각을 변환'), names the exact output form ('UTC 오프셋이 붙은 ISO 8601 문자열 iso_datetime'), and is clearly distinguishable from the other datetime siblings (diff, add_business_days, lunar conversions).

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 explains how input is interpreted (offset present vs. absent, DST overlap) but never says when to pick this tool over alternatives such as datetime.diff or units.time_small_convert, nor any when-not conditions. Usage is implied by the conversion semantics rather than stated.

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