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

No annotations are provided, so the description carries the burden. It indicates a read-only search (finding destinations) and implies a list of options, but does not detail return format, potential limitations, or whether any side effects occur. This is acceptable for a search tool but lacks explicit behavioral detail.

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 a single, concise sentence without redundancy. It efficiently conveys the purpose and usage condition, earning a perfect score for conciseness.

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 is a search function with no output schema, the description provides sufficient context: it returns lower-priced destinations. It does not specify the output format (e.g., list of destinations with prices), but this is implied by the nature of the tool and consistent with sibling search tools. Completeness is high but not exhaustive.

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?

All parameters in the schema have descriptive properties (e.g., from: 'Departure IATA code or city name', depart: 'Departure date in YYYY-MM-DD format'). The schema coverage is 100%, so the baseline is met. The description does not add extra parameter context, but it is not necessary given the schema's clarity.

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 function: finding lower-priced destinations from a given departure city when the user is flexible about the destination. It uses a specific verb ('Find') and resource ('destinations'), distinguishing it from flight-specific or calendar tools.

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 specifies the condition for use ('when the user is flexible about where to go'), providing clear guidance. It does not explicitly mention alternatives, but the sibling tool names imply differentiation (e.g., flex calendars, flights search), so the usage context is adequately conveyed.

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