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

Beyond the readOnlyHint annotation, the description discloses key behavioral traits: the operation takes about a minute, returns a quoteReference immediately, and requires that reference to retrieve the quote—noting it is the only way to retrieve it. This is valuable, non-obvious context.

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?

Four dense, purposeful sentences. The description front-loads the core purpose and output, then provides usage guidance and async behavior. No filler or redundancy.

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?

Despite having no output schema, the description conveys what results to expect (cheapest, fastest, fewest stops with actual tickets), explains the asynchronous flow, and warns about the retrieval dependency. This is comprehensive for a tool of this complexity.

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 all six parameters. The description adds contextual framing about multi-stop trips and fare structures but does not add new parameter-level semantics beyond the schema.

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 tool prices a complete multi-stop or round-the-world trip and returns multiple ticketing options. It also distinguishes itself from sibling tools like fare_quote and itinerary_quote_status, making its purpose unmistakable.

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?

Explicitly says when to use this tool ('trips that will not go on a single fare, which is most itineraries with 3+ stops') and names the alternative: 'use fare_quote when you want one specific itinerary on one ticket.' It also directs users to itinerary_quote_status for fetching results.

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