Daylight-saving changes

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

No annotations are present, so the description carries the burden of explaining behavior. It discloses the key output traits: exact UTC instant and offsets before/after the change. This is meaningful for an agent. It could say more about empty results or return shape, but for a simple query tool this is reasonably transparent.

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. The first states the output content, and the second provides a practical use case. Every sentence earns its place, and there is no filler.

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 low-complexity, two-parameter tool with no output schema, the description gives enough context: what is returned, the time detail, and the intended use. It could be slightly richer by noting what happens when a zone has no daylight-saving changes, but nothing critical is missing for normal use.

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%, with clear descriptions for year ('Calendar year, default this year') and zone ('Place or IANA zone'). The description adds no extra parameter meaning beyond the schema, so the baseline of 3 applies.

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 identifies what the tool provides: daylight-saving clock changes for a place/year, with UTC instants and before/after offsets. It does not use a strong verb like 'returns' or 'lists', but the resource and output content are specific. It is distinguishable from time-related siblings by focusing on DST transitions.

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 gives an explicit use case: checking whether a recurring call moves for one participant in March or October. This is practical and helps an agent know when this tool is relevant, though it does not name alternatives or explicitly say when not to use it.

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