select_flight

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

With no annotations, the description carries the burden of disclosure. It explicitly states that this tool modifies state by 'adds the flight to your booking session', which is a key behavioral trait. It doesn't discuss idempotency or error handling, but it gives enough for an agent to understand the side effect.

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 two concise sentences, front-loaded with the primary action and immediately providing context and outcome. Every word adds value, with no redundancy or filler.

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?

The tool has simple parameters and no output schema, and the description covers the essential context: when to use it (after searching) and what it does (adds to the booking session). It doesn't explicitly mention return values or errors, but for this type of selection tool, the description is sufficiently complete for agent use.

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% for both parameters, so the schema already explains the meaning and roles of outboundFlightId and returnFlightId. The description only loosely mirrors these ('outbound and optionally a return'), adding no new semantic detail, so the 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?

The description clearly states the action ('Select') and the resource ('an outbound and optionally a return flight'), and it specifies the context ('after searching') and the effect ('adds the flight to your booking session'). This distinguishes it from sibling tools like search_flights and get_flight_details.

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?

It says to use this tool 'after searching', implying search_flights is a prerequisite. It also clarifies that returnFlightId is optional for round trips, giving guidance on when to include it. However, it doesn't explicitly name search_flights or mention alternative tools for when not to use this, so it's not a full 5.

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