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

No annotations are provided, so the description carries the full burden. While 'Check whether' implies a read-only query, it does not disclose the return format, default timezone behavior, or any auth/rate-limit considerations.

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 short and front-loaded, with no wasted sentences. The only minor redundancy is the 'Is Dst:' prefix, which largely restates the tool name.

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 tool with three parameters, no annotations, and no output schema, the description is incomplete. It omits the return value, default timezone handling, and any guidance on how the tz and timezone parameters interact.

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 baseline is 3 even though the schema descriptions are generic ('Tz to process', 'Date to process', 'Timezone to process'). The description adds little beyond noting that date is optional and that the check is for the local timezone, and it does not clarify the difference between tz and timezone.

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 states a specific check operation and resource: whether a date is in Daylight Saving Time for the local timezone. It is clear but does not distinguish itself from sibling date/time tools such as x402-daylight-savings or x402-timezone.

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 does not explain when to use this tool versus alternatives, nor does it mention prerequisites or exclusions. 'Provide optional date' is a parameter note, not usage guidance.

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