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

Annotations already declare this as read-only, idempotent, non-destructive, and closed-world, while the description adds important workflow behavior: the tool returns data only and must be followed by render_destination_weather. It also discloses the Foreca source, credit requirement, and place_url handoff, which are not in 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 front-loaded with purpose and then structured as routing rules, exclusions, prerequisites, and post-call requirements. It is longer than typical but mostly information-dense, with minor repetition around when-to-visit behavior.

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 tool's one-parameter schema, existing output schema, and read-only annotations, the description covers the remaining decision-critical context: correct input format, fallback resolution, sibling alternative, attribution, and required rendering follow-up. Nothing essential for correct selection or invocation 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% and the single destination_handle parameter is already documented with examples. The description adds meaningful routing semantics by saying to use a sitemap handle and to call resolve_destination first when only a city, country, or airport name is available, though its examples partly repeat the schema.

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 and resource set: current weather, forecast, climate, and when-to-visit notes for one place. It also distinguishes the tool from get_destination_info by naming generic-info queries such as "info on Dubai" and "what is Tokyo like."

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?

It explicitly lists when to use the tool, when not to use it, and the correct alternative for generic destination information. It also gives prerequisites: use a sitemap handle or call resolve_destination first, then call render_destination_weather afterward.

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