Historical Weather

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

Annotations already declare the tool as read-only, idempotent, and non-destructive. The description adds behavioral context: date range constraints (back to 1940), that current/future dates are rejected, and that it returns weather + astronomy. No contradictions 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?

The description is three short sentences with zero wasted text. It front-loads the purpose, then constraints, then requirements. Every sentence earns its place.

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 7 parameters with full schema coverage and no output schema, the description adequately covers the key behavioral constraints (date validity, parameter requirements) and high-level return content. It is complete enough for a tool in a weather domain with clear 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 coverage is 100%, so baseline is 3. The description adds meaning by clarifying the mutual exclusivity of location parameters ('provide at least one of'), which is not obvious from the schema alone. Also mentions 'astronomy', which hints at additional output beyond weather.

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 historical weather data'), the resource ('for a specific past date back to 1940'), and distinguishes from siblings by specifying 'historical' vs current/forecast. The mention of astronomy and granularity (daily/hourly) adds specificity.

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 explicitly states that only past dates are allowed and that at least one of location, lat+long, or ip must be provided. While it doesn't explicitly contrast with siblings like weather_current or weather_forecast, the context of historical data implies the appropriate use case.

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