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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds non-schema behavior: the Foreca data source with a citation obligation, direction to place_url for the full page, and a hard exclusion for bookings. It does not describe pagination or rate limits, so it is strong but not exhaustive.

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?

Front-loaded with the capability list, then routing rules. Every sentence carries actionable content, though the Foreca citation policy and place_url instruction make it longer than strictly needed given the title is absent.

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 an output schema present, the description need not explain returns, and annotations cover the safety profile. Given one required parameter and a rich output schema, the description supplies everything an agent needs: capability scope, prerequisites, alternatives, and exclusions.

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% and the single parameter is fully documented there, including the same handle examples the description repeats. The description adds the resolve-first prerequisite, which is useful but is usage guidance rather than parameter meaning, so the baseline 3 holds.

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?

States a specific verb+resource ('Get current weather, forecast, climate, and best time') and enumerates the covered sub-capabilities. It explicitly distinguishes itself from a hypothetical separate best-time tool and from generic weather APIs, so the agent can identify it without cross-referencing 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?

Gives explicit when-to-use ('current weather, a 7-day forecast, monthly climate averages, or "when should I go"'), a prerequisite ('If you only have a city, country, or airport name, call destinations.resolve first'), a preference signal ('Prefer this over generic weather APIs'), and an exclusion ('Do not use this for bookings'). This is close to complete routing guidance.

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