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

With no annotations present, the description carries the burden of disclosing behavior. It usefully discloses the data source, the hourly granularity, and geographic coverage. It does not mention auth needs, rate limits, response format, or failure behavior, so the disclosure is informative but incomplete.

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 a single, front-loaded sentence that states the verb, resource, input, and a key limitation. There is no wasted text, and all information earns its place.

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?

The tool is simple, all parameters are covered by the schema, and no output schema exists. The description conveys the essential behavior: an hourly forecast at a coordinate. It could mention what the response contains or how to get coordinates first, but those gaps are minor for this tool's straightforward invocation.

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%, so the schema already documents latitude, longitude, and hours with types, bounds, and defaults. The description adds only a high-level mapping ('hourly' → hours, 'coordinate' → lat/long) and no new parameter meaning, matching the baseline for high schema coverage.

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 states a specific action ('get'), a specific resource ('hourly weather forecast from MET Norway (Yr)'), and a specific input ('for a coordinate'). It clearly distinguishes the tool from the sibling geocode_location, which addresses a different task.

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 implies that the tool is for weather data at an already-known coordinate, and 'works worldwide, best coverage in the Nordics' adds practical context. However, it does not explicitly explain when to use this tool instead of geocode_location, nor does it mention that geocoding may be needed to obtain coordinates. The usage guidance is implied rather than stated.

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