Climate normals 1961-1990 vs 1991-2020

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

Annotations only cover read-only and open-world; the description adds cost ('Free'), the derived change metric semantics, default expansion behavior when month is omitted, and prcp aggregation semantics. It does not say anything about response shape or rate/limits, 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 short sentences plus a one-word cost flag, all front-loaded; the earliest and most consequential caveats (month omission, annual prcp totals) come after the purpose, and nothing is 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 6-parameter read with full schema coverage and no output schema, the description supplies the purpose, cost, and the two behavior traps most likely to cause misreads. It stops short of describing what a returned record contains for each time_scale, which would be the remaining gap.

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 already 100%, so 3 is the floor; the description goes beyond it by explaining that omitting `month` with time_scale=mon returns all 12 months, and that annual precipitation is reported as a yearly total (units beyond the schema's °C/mm note). Day/ann interactions remain unstated.

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 the specific resource (climate normals) plus the two baselines covered and the derived change field ('newer minus older'), which is real information beyond the name. It does not distinguish itself from siblings like get_weather or request_point_history, so an agent must still infer when normals beat an actuals call.

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?

'Free' is a genuinely useful selection hint against paid/download siblings such as request_point_history or request_area_download, and the time_scale notes imply the intended granularity. But there is no explicit when-to-use or when-not-to-use statement and no sibling is named.

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