get_road_weather

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

Annotations already declare read-only, idempotent, open-world semantics, and the description adds context the annotations cannot convey: an error result (isError: true) when TRAFIKVERKET_API_KEY is missing/invalid or the upstream API is unreachable, plus Sweden-only coverage and a 10-minute observation window. This is exactly the operational detail an agent needs before calling.

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 tightly packed sentences with zero filler: what it returns, the observations-vs-forecast distinction, then failure modes and coverage. The core capability is front-loaded before the caveats.

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?

No output schema exists, yet the description effectively enumerates the returned fields and their units, and it documents error behavior and geographic coverage. Nothing an agent needs in order to call this correctly is missing.

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%, with min/max bounds and defaults documented for latitude, longitude, radiusKm and limit. The description only restates the point-anchored nature of the query and adds no format or tuning guidance beyond the schema, 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?

Names a specific verb and resource ('Get measured road weather'), the data source (Trafikverket roadside stations), and the anchoring parameter ('nearest to a point'). It then enumerates the exact measurements returned, so an agent knows precisely what it gets without opening the 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?

Explicitly frames when NOT to use it: 'These are actual observations, not a forecast; use a forecast source such as SMHI for future weather.' That is a real routing rule. It does not reference the sibling tools (search_stations, get_road_situations), so a small amount of alternative-selection guidance is missing.

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