Get precipitation nowcast

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

With no annotations provided, the description must carry the full behavioral disclosure. It states the data is radar-based and minute-by-minute, and it clearly warns that it is Nordic region only. However, it does not describe the return format (e.g., units of precipitation, a series vs. a single value), nor does it explicitly state that the operation is read-only (though that is implied). This is adequate for a simple read tool but leaves the response shape unspecified, which is a gap given no output schema.

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 two short sentences that front-load the most critical information: the precision (minute-by-minute), the duration (next 2 hours), the data source (radar), and the geographic scope (Nordic region only). The rhetorical question at the end encapsulates the purpose without extra verbosity. Every word serves a purpose.

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 only two parameters and no output schema, the description conveys the core functionality and limitations well. However, because there is no output schema, the description should at least hint at what the tool returns (e.g., precipitation intensity in mm/h or a binary umbrella recommendation). The current wording leaves the return structure ambiguous, which an agent might need to know for downstream formatting. This is a noticeable completeness 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?

The input schema already fully describes latitude and longitude with ranges and degrees. The description adds meaningful semantic value by constraining usage to the Nordic region, implying that coordinates outside this region will not produce valid results. This is a functional addition beyond the schema's generic descriptions, though it does not add units or formats that are already provided.

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 specifies the resource (minute-by-minute precipitation), its temporal horizon (next 2 hours), data source (radar-based), geographic scope (Nordic region only), and the exact user question it answers ('do I need an umbrella right now?'). This distinguishes it from siblings like get_forecast (longer-term) and get_historical_weather (past). The verb 'get' and resource name 'nowcast' match the tool name and title.

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?

The description provides clear context: the tool is for very short-term precipitation (2 hours) and is restricted to the Nordic region. However, it does not explicitly mention when to use this tool instead of get_forecast or get_historical_weather, nor does it state any exclusions beyond the geographic constraint. The time horizon implies a boundary, but the lack of explicit alternative routing leaves some inference required.

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