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

Annotations already declare readOnly, non-destructive and open-world access, so the safety profile is covered. The description adds genuinely useful context beyond that: hourly model at 1 km resolution, up to 61 hours of range, and a required attribution step (cite the data source with license). It does not discuss rate limits or failure modes, but with annotations covering safety this is adequate.

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?

Front-loaded with the resource and content, followed by resolution/range, the warning caveat, example questions and the attribution instruction. Every sentence carries information, though the example-question block and attribution note make it longer than strictly minimal.

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?

With no output schema, the description carries the full burden of describing return values, and it does so thoroughly (6-hour blocks, listed variables, daily aggregates). It also communicates the resolution, time horizon and attribution requirement, leaving nothing an agent needs in order to call it correctly.

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 both parameters (ort with its name/GKZ/coordinate formats, stunden with range 1-61 and default) are already fully documented in the schema. The description's mention of "bis 61 Stunden" echoes the schema rather than adding syntax or format meaning, so the baseline 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?

States a specific resource (GeoSphere Austria forecast for an Austrian municipality) and details exactly what the response contains: 6-hour blocks with temperature, precipitation, snow share, peak gust, wind and snow line, plus daily values. This rich content description implicitly separates it from siblings like niederschlag_jetzt (current precipitation) and the flood/warning tools, though no sibling is named explicitly.

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?

Provides three concrete example questions that map directly to the tool's forecast use case, and adds a boundary condition ("Keine amtliche Unwetterwarnung") telling the agent this is not for official severe-weather warnings. It stops short of explicitly naming alternatives for the current-conditions or flood siblings, so routing is left partly to inference.

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