search_flights

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

With no annotations, the description carries the full burden and adds valuable behavioral context: deep_search is slower but more precise, max_results caps options per bucket, and round-trip prices are the total fare. These details go beyond the schema and help set expectations for the agent.

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 structured as a clean Args list with terse, informative lines, and the closing note about round-trip fare/token adds high-value context without redundancy. For a tool with 15 parameters, the length is justified and 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 the 15 parameters and lack of output schema, the description covers parameter formats, conditional requirements, and key behaviors like the round-trip token flow. It could be slightly more complete by describing the response envelope or error behavior, but it provides enough for an agent to select and invoke the tool successfully.

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?

The schema has 0% description coverage, so the description fully compensates by providing IATA code examples, comma-separated multiple origins, date formats, ISO 4217 currency, per-bucket max_results, and the deep_search tradeoff. Each parameter receives meaningful elaboration that turns the raw schema into actionable guidance.

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 uses the specific verb 'Search', identifies the resource 'Google Flights (via SerpAPI)', and scopes it to 'between two airports', which cleanly distinguishes from multi-city search and other flight tools. The mention of departure_token passing to get_return_flights further clarifies its role in the search workflow.

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 guides round-trip usage by noting that the departure_token can be passed to get_return_flights for return options, and clarifies when return_date is required vs. ignored. It does not explicitly contrast with search_multi_city or track_price, but the 'between two airports' scope and token handoff provide strong contextual guidance.

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