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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety and external-reach profile is covered. The parenthetical '(departing-leg offers)' adds genuine value by telling the agent what the results represent, but nothing is said about auth needs, rate limits, or how round-trip return legs are handled.

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?

A single efficient sentence with no filler, and the key constraint (between two IATA codes) is front-loaded. It is appropriately sized but perhaps too terse given the parameter surface.

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 9-parameter search tool with 0% schema coverage, the description leaves most parameters and trip semantics undocumented. An output schema exists, so return values need not be explained, but the input side is materially under-specified.

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 0% across 9 parameters, so the description carries the full documentation burden. It clarifies only that origin/destination are IATA airport codes; the other seven parameters (trip_type, cabin_class, adults, locale, currency, departure_date, return_date) get no meaning, format, or default hints.

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 names a specific verb (Search) and resource (Expedia flights) and clarifies the operation is between two IATA airport codes, which distinguishes it from expedia_properties_search and expedia_activities_search. It does not, however, distinguish it from the other flight-search siblings (agoda_flights_search, booking_flights_search) beyond the brand name.

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?

There is no guidance on when to use this tool versus alternatives, no prerequisites (e.g., needing IATA codes from expedia_locations_search), and no mention of one-way vs round-trip conditions. Usage must be entirely inferred from the single declarative sentence.

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