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

Annotations already establish read-only, open-world, non-destructive behavior, but the description adds substantial context beyond them: an anti-fabrication rule (values only from tool output), the GeoNutzV attribution obligation that travels with the output, and one-call-per-location semantics. This is exactly the kind of disclosure structured fields cannot carry.

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?

Dense and long, but front-loaded and organized into bolded sections (When to use / When NOT / Required args / Typical chain / Anti-fab). A little redundancy between the required-args recap and the schema, but nearly every sentence carries routing or safety value.

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 still tells the agent what the return carries (the additive attribution object) and how to cite it, plus the chaining path through search_place. Complete for a read-only, coordinate-driven lookup.

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%, so lat/lon/units/lang are already documented, but the description adds a real constraint absent from the schema: coordinates must originate from search_place and never from estimation. That elevates it above the baseline 3, though it largely restates the unit/language defaults.

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 ('Aktuelles Wetter zu Koordinaten') and explicitly contrasts itself with get_weather_forecast and get_tide. An agent can distinguish it from all siblings without opening a schema.

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 explicit 'When to use' and 'When NOT to use' sections with named alternative tools for each exclusion (forecast >1h, tides), plus multi-call and multi-day routing guidance. Nothing is left to inference.

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