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

With no annotations, the description bears the full burden of behavioral disclosure. While 'forecast' implies a read operation, no statements confirm non-destructiveness, rate limits, or caching behavior. The description is insufficient for an agent to assess safety implications.

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, concise sentence with essential keywords front-loaded. However, brevity sacrifices necessary detail (e.g., coordinate constraints). It earns a 4 for efficiency but could incorporate more information without becoming verbose.

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 simple tool (2 params, no annotations, no output schema), the description should be self-sufficient. It lacks parameter semantics, usage guidance, and behavioral details. Agent cannot reliably use it without external knowledge, especially among many weather-related siblings.

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 0%, so the description must compensate. It mentions 'US lat/lon' but does not define valid ranges (e.g., latitude 25-50, longitude -125 to -65) or format expectations. The schema only declares type: number; the description adds minimal practical meaning.

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 'Detailed NWS 7-day forecast for US lat/lon', specifying the source (NWS), duration (7-day), and geographic scope (US). This distinguishes it from sibling tools like weather_alerts (alerts), weather_bias (bias analysis), and weather_current_global (current conditions globally).

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?

No explicit guidance is provided on when to use this tool versus alternatives. For example, it does not differentiate from weather_current_global for current conditions or weather_alerts for warnings. The agent is left to infer context from sibling names.

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