Search flight prices

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

Annotations already declare readOnly/openWorld/idempotent, and the description adds substantive behavior beyond them: cost accounting (2 credits per uncached search), 30-minute caching semantics, indicative (non-bookable) prices, and that fulfillment happens off-platform. This is exactly the extra context an agent needs to decide whether to spend credits.

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-loads the core operation and mode distinction, then layers output shape, constraints, cost, and disclaimer. Four sentences, each carrying distinct information with no repetition of the schema.

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?

With no output schema, the description takes on the return-value burden and does so explicitly (airline, total price, stops, duration, local departure/arrival times). Combined with cost, cache, and booking caveats, an agent has everything needed to call and interpret this tool.

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 the schema already documents every parameter including defaults and formats. The description restates the IATA 3-letter constraint and return_date's one-way semantics, adding only marginal value over the schema, so the baseline 3 applies.

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+resource (search live flight prices) and immediately defines the two operating modes with their differentiator (one-way vs. return_date round trip). It also names the sibling search_airports as the prerequisite when only a city is known, so an agent can place it precisely among the five siblings.

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 explicit usage context: one-way vs. round-trip driven by return_date, and a clear alternative/precondition for the IATA-code requirement (call search_airports first). The caching note (identical searches cached 30 min) further informs when re-calling is wasteful.

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