env_weather

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

Annotations already declare read-only, idempotent, and non-destructive behavior. The description adds context about the free tier licensing and the need to set OPEN_METEO_API_KEY and OPEN_METEO_BASE_URL for commercial use, which goes beyond the annotations. It also notes no API key is needed for the free tier, adding useful behavioral context.

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 five sentences, with the purpose stated upfront. It is concise and each sentence adds value, though it could be slightly trimmed without losing meaning.

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 weather tool with a full output schema and comprehensive annotations, the description is complete. It covers the API provider, licensing, use cases, and data returned. No critical missing information is apparent.

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 already provides descriptions for all three parameters (location, days, include_hourly) with 100% coverage, so the description adds no additional parameter guidance. The baseline of 3 is appropriate as the schema carries the semantic load.

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 the action (Get) and resource (current weather and multi-day forecast) for a location. It lists the specific data fields returned (temperature, precipitation, wind, cloud cover, humidity, visibility) and names the provider (Open-Meteo), distinguishing it from sibling tools like sun_moon or terrain_elevation.

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 provides explicit use cases such as delivery scheduling, field work, construction, outdoor events, agricultural spray windows, and travel decisions. However, it does not mention when not to use the tool or name alternative tools, so it lacks explicit exclusions.

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