vt_list_destinations

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

Annotations already mark it as read-only and open-world. Description adds that this is cached reference data, which is crucial for agents to understand potential staleness. Also lists the exact data fields returned, providing full behavioral transparency beyond 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?

Two focused sentences with no superfluous words. The first sentence states what the tool does and its output; the second gives guidance on usage and caching. Every sentence adds value.

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 simple list tool with one optional parameter and no output schema, the description completely covers what it returns, how to use it, and important caching behavior. No gaps remain.

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 covers the single optional parameter (campaign_value) with a description. The tool description does not add further semantics about the parameter beyond what is already in the schema, so baseline score of 3 is appropriate.

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?

Description clearly states it lists destinations (cities, regions, countries) with specific fields like ids, parent hierarchy, IATA codes, time zones, coordinates. Distinguishes itself by mentioning how destinationId can be used with other tools like vt_search_products and vt_search_attractions.

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?

Indicates that the data is reference and cached, and suggests using destinationId with specific search tools. While it does not explicitly state when not to use it, the context is clear for an agent to infer its purpose as a lookup for destination data.

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