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

With no annotations provided, the description carries the behavioral burden. It discloses the data source (radar-based), temporal resolution (minute-by-minute), forecast horizon (next 2 hours), and geographic restriction (Nordic region only). It omits response format details and non-coverage behavior, but enough behavioral context is present for safe selection and invocation.

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, each adding distinct value: what is returned, the time horizon and source, then the use case. No wasted words or duplication of the title or schema.

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, low-complexity tool with two well-documented parameters, the description is sufficient for an agent to select and invoke it. The lack of an output schema means the response format is not explicitly described, but the description strongly indicates a precipitation series, which is enough to act.

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 for the two parameters is effectively complete (latitude/longitude, with ranges and descriptions provided). The description adds a meaningful geographic constraint 'Nordic region only', but it does not add much per-parameter semantics beyond what the schema already includes.

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 the tool's function: minute-by-minute precipitation for the next 2 hours, based on radar data. It also defines the geographic scope (Nordic region only) and includes an applied use case ('do I need an umbrella right now?'), which distinguishes it from sibling tools like get_forecast and get_ocean_forecast.

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 gives a clear context for use: immediate, short-horizon precipitation checks. It does not explicitly name alternatives or say when not to use it, but the time window ('next 2 hours') and 'umbrella right now' framing make the intended scenario obvious.

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