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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds meaningful behavioral detail beyond the schema, including the Seattle location, the day-by-day forecast format, and go/no-go recommendations based on temperature, rain, and wind. No contradiction with annotations.

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?

Two concise sentences with no filler: the first states the purpose and output, the second gives concrete use cases. The core function is front-loaded, and every sentence contributes to selecting or invoking the tool correctly.

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?

With full schema coverage, a rich set of annotations, and an output schema present, the description completes the picture by specifying location, use cases, and the nature of the returned recommendation. Nothing an agent needs in order to decide whether to call this tool 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 coverage is 100%, so the baseline is 3, but the description adds useful meaning by linking projectType to project-specific weather requirements (temperature, rain, wind). This helps an agent understand that projectType influences the suitability thresholds. The days parameter remains fully documented by the schema, so no critical information is missing.

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 verb ('Check'), a specific resource ('upcoming weather in Seattle'), and a clear purpose ('suitable for an exterior construction project'). It further distinguishes the tool by describing its output ('day-by-day forecast with go/no-go recommendations') and listing relevant project types, so an agent can tell it apart from the many get_* siblings.

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 clear context: use this tool to evaluate upcoming weather for exterior work like painting, decking, roofing, etc. It does not explicitly name alternatives or exclusion conditions, but none of the sibling tools appear to compete with this weather-specific function, so the context is sufficient for selection.

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