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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the agent knows it is a safe read operation. The description adds that the output is editorial-style and focused on current weather, which is useful context beyond the annotations. However, it does not describe the return format, pagination, or any other behavioral traits, but given the annotations cover safety, this is acceptable.

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 sentences long, with the purpose front-loaded and the parameter note following naturally. Every sentence earns its place; there is no filler or redundant information. It is compact while conveying core semantics.

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 read-only tool with three optional parameters and no output schema, the description is nearly complete. It covers the purpose, scope, and the filter options (albeit not lang). The only missing piece is an explicit note on what the output looks like, but since there is no output schema and the tool is editorial, this is a minor gap. Overall, an agent can call this tool correctly with the given information.

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 description explains that 'country' takes an ISO-2 code and that both country and region are optional filters, giving meaning beyond the schema which has no descriptions. However, the 'lang' parameter is not mentioned at all, and the format for 'region' is unspecified. With 0% schema coverage, the description partially compensates but leaves at least one parameter unexplained.

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 today's Daily Snow editorial with expert-style regional briefs on current weather across the Alps and beyond. It uses a specific verb ('briefs') and resource ('Daily Snow editorial'), and the phrase 'actually doing' implies current conditions rather than forecasts. However, it does not explicitly contrast with sibling tools like conditions or snow_forecast, so it is not fully differentiated by description alone.

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 use for a daily editorial summary of current conditions, but it never explicitly says when to prefer this over sibling tools such as snow_forecast or conditions. There is no mention of alternatives or specific exclusions, leaving the agent to infer the appropriate context. The 'Today's' and 'actually doing' hints, but the guidance is not explicit.

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