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

With no annotations, the description must disclose behavioral traits itself. It lists return fields such as prices and carbon emissions, but does not mention any limitations, prerequisites, or operational caveats. The verb 'Search' implies a read-only operation, yet no explicit safety or side-effect information is provided.

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 a single, front-loaded sentence that begins with the action and resource, then lists key return fields. It is concise and free of redundant information.

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 a moderately complex schema (9 optional parameters) and no output schema, but the description covers the core purpose and return values. It falls short only in not addressing sibling-tool differentiation or potential behavioral caveats, making it mostly complete for basic invocation.

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?

All 9 parameters have descriptions in the input schema (100% coverage), so the schema already documents their syntax and meaning. The tool description adds no extra parameter-level guidance, such as how stops or travel_class affect results. Baseline 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 tool's action ('Search') and resource ('round-trip or one-way flights between airports'), and lists what it returns. However, it does not explicitly differentiate from sibling tools like one_way_search or multi_city, which also search flights.

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 implies the tool is for general flight searches, covering both round-trip and one-way options. It provides no explicit alternatives or exclusions, so the agent is left to infer when to choose this tool over specialized siblings.

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