Weather

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

Annotations already declare readOnlyHint=true, destructiveHint=false, idempotentHint=true, covering safety. The description adds value by specifying data source (DWD), fields (temperature, wind, precipitation), and clarifying it's current conditions only (not forecast). No contradictions with annotations.

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 sentences with no wasted words. First sentence states core purpose, second adds details, third provides usage alternatives. Front-loaded with essential information.

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 simple tool with one parameter and an output schema, the description covers what, source, usage boundaries, and alternatives. Complete for an agent to select and invoke 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 coverage is 100% with one parameter 'slug' described. The description adds meaning by stating the slug comes from list_cities tool and giving examples ('berlin' or 'hamburg'), which helps the agent understand valid inputs beyond the schema definition.

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 states 'Get current weather observations for a German city', specifying verb (Get), resource (weather observations), and scope (German city). It differentiates from siblings by explicitly contrasting with forecasts, weather warnings (get_city_resource), and city overview (get_city_overview).

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?

Explicitly states when to use (current weather), when not (not a forecast), and provides specific alternatives: for warnings use get_city_resource with resource='weather-warnings', and for broader city questions use get_city_overview. This gives clear guidance on tool selection.

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