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

Annotations already declare the tool is read-only and idempotent; the description adds valuable context by stating that no API key is required (open data, Creative Commons BY 4.0) and detailing the exact output fields returned. This goes beyond the annotations to describe data licensing and content.

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 relatively long but well-structured, front-loading the core purpose and then enumerating the output fields and scale. Every sentence provides useful information without redundancy, though the list of accumulated precipitation days could be trimmed.

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?

Given the tool's complexity (many output fields, geographic constraints, licensing), the description is comprehensive. It explains the output values, the fwiindex scale, geographic bounds, and licensing, leaving little ambiguity for an agent to correctly invoke the tool.

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 schema descriptions for all three parameters are complete with examples and bounds. The description reinforces the geographic limits and explains the fwiindex scale, but does not add substantial new meaning for the parameters themselves; it mostly reiterates schema information.

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 it provides a 7-day daily fire weather risk forecast for Sweden using the Canadian FWI system. It lists specific output metrics and explicitly states the geographic scope, distinguishing it from other SMHI weather tools like forecast, observations, and warnings.

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 clearly indicates this tool is for fire risk forecasts in Sweden, and the geographic constraints are explicit. It does not explicitly mention when to use this over sibling SMHI tools, but the specialized fire-risk focus makes the use case clear and unambiguous.

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