Google Flights search

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

Annotations only cover the safety profile (readOnly, openWorld, non-idempotent, non-destructive); the description adds the operationally critical details an agent needs — 5–20 second latency and explicit per-flight billing cost ($0.20/1,000 flights), which is essential for choosing max_results.

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 purpose, then returns, mode behavior, usage, latency and cost. Every sentence carries distinct information; the return-field list is justified because no output schema exists.

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 10-parameter, read-only, open-world search with no output schema, the description supplies the return shape, default trip mode, expected latency, and billing model — everything an agent needs to call it correctly and size its request.

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 description coverage is 100%, so every parameter including defaults, ranges, patterns and enums is already documented. The description's parameter notes (one-way default, return_date meaning round trip, omitted departure_date) largely restate the schema, so it meets the baseline without adding new syntax or constraints.

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 and resource with scope: 'Search Google Flights for one route and date.' The enumerated return fields (prices, airlines, times, CO2, best-flight flag) make it unmistakably distinct from siblings like search_hotels or search_google_shopping.

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 clear use context ('for flight prices, schedules and the cheapest or fastest options between two places') and a mode rule ('One way by default; set return_date for round-trip prices'). It stops short of naming alternatives or stating when not to use it, so it is clear but not complete.

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