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mtnrabi

google-flights-mcp

FlightPowers: search round-trip flights

search_roundtrip_flights
Read-only

Search live round-trip flight fares with flexible dates and multiple destinations. Get total price, per-leg details, and a booking link for any return trip.

Instructions

FlightPowers round-trip fare search: live prices read from Google Flights, priced as paired legs rather than two separate one-ways. Input: origin and destination IATA codes -- the destination may be several codes, as "BCN,LIS,ATH" or ["BCN","LIS","ATH"] -- a departure date or range, and either a return date or a trip length in nights. Returns the total price for both legs, per-leg airline, stops and duration, and a single bookable buy_link for the trip.

Use it for any return-trip fare question. For a flexible search make ONE call: pass departure_date_from / departure_date_to for the outbound range and nights instead of return_date to compare trip lengths -- '5 to 7 nights in Rome sometime in May' is one call.

Each date/destination combination is one billed request; the count and the plan's remaining quota come back in api_usage.

by_destination carries one entry per destination you asked for -- empty ones included, each with a reason -- so read it before telling a user a destination has no flights.

Requires the caller's own RapidAPI key for the Google Flights Live API. Get one (free tier available) at https://rapidapi.com/mtnrabi/api/google-flights-live-api, then pass it as an x-rapidapi-key header (preferred), a ?rapidapi_key= query parameter on the server URL, or your client's own API key field -- first non-empty wins. Usage counts against the caller's own RapidAPI plan, not ours; every response reports what it spent and what is left in api_usage.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
limitNoMaximum trips to return, after merging and sorting.
nightsNoTrip length in nights; a number, or a list like [5, 6, 7]. The return date is derived from each departure date.
sort_byNo"best", "price", or "duration". Applied across all results.best
currencyNoISO currency code, default "usd".usd
max_priceNoOnly return trips at or below this total price.
seat_typeNo1 economy, 2 premium economy, 3 business, 4 first.
passengersNoPassenger counts as [adults, children, infants].
to_airportYesDestination airport. One IATA code ("BCN"), several separated by commas ("BCN,LIS,ATH"), or a list (["BCN","LIS","ATH"]) -- every shape is accepted and the destinations are compared in the same search.
return_dateNoFixed return date. Use this OR nights, not both.
from_airportYesOrigin IATA code, e.g. "TLV". One origin per search; a second one is refused rather than searched.
max_searchesNoCap the billed requests this call may make. Lower it to spend less of the plan's quota on a wide search; the range is then sampled evenly rather than cut short.
use_fallbackNoLeave unset. Switches the search to a second, independent flight data source instead of the usual Google Flights page read. Unset already escalates to that source once, automatically, after a search's retries have failed. true forces it inline on every attempt -- much slower, and it can time out. false disables it entirely, that automatic retry included.
departure_dateNoSingle outbound date, "YYYY-MM-DD".
max_return_stopsNoMaximum stops on the return leg.
departure_date_toNoLast date of an outbound range.
departure_date_fromNoFirst date of an outbound range.
max_departure_stopsNoMaximum stops on the outbound leg.
return_airline_codesNoRestrict the return leg to these airlines.
departure_airline_codesNoRestrict the outbound leg to these airlines.

Output Schema

TableJSON Schema
NameRequiredDescriptionDefault
messageNoPresent when there is something the model must relay to the user rather than silently absorb -- no results, a degraded search, a missing key or a spent quota.
partialNoPresent when some searches failed but others succeeded. Plain text saying how much of the request the results cover.
resultsYesThe itineraries or properties found, already sorted and deduplicated. An empty array is only meaningful when search_status is 'empty'.
api_usageNoWhat this call cost the caller's own RapidAPI plan, and what remains on it. Present on every response that reached the upstream, including a degraded one -- a search that failed was still billed.
signup_urlNoWhere the caller subscribes or changes plan.
result_countNo
needs_api_keyNoTrue when no usable RapidAPI key arrived with the call, or the upstream rejected the one that did. No search was run and nothing was billed; signup_url and message say how to fix it.
search_statusNoWhether the underlying search actually completed, read from the backend's X-Search-Status header. 'ok': every combination searched returned results. 'empty': the search completed and Google genuinely has no itineraries for it -- a real answer, not a failure. 'partial': some combinations returned results and some failed, so the list is incomplete. 'degraded': every combination failed, so the search did not happen and an empty list means nothing; this case is also flagged with isError: true and is safe to retry.
by_destinationNoOne entry per destination the REQUEST asked for, in request order, present whether or not that destination has any flights in `results`. A destination with an empty `rows` array is a hole in the answer, and `reason` says which kind of hole: 'no_flights' (searched, answered, Google has nothing), 'search_failed' (searched and the search errored, so nothing is known), 'not_in_limit' (searched, found flights, none fitted in `limit`) or 'not_searched' (never searched -- the per-call fan-out cap sampled it away). 'ok' means it has rows. Read this rather than inferring coverage from `results`: a destination missing from `results` looks identical to one that has no flights, and they are not the same answer. `rows` are the same row objects that are in `results`, in the same order -- nothing here is data the answer does not already contain.
quota_exhaustedNoTrue when the caller's RapidAPI plan has no requests left for the current period.
search_coverageNoWhat was actually searched. Present whether or not the request was truncated, so a model can state honestly what its answer rests on.

Schema Changelog

Changes observed during successful MCP inspections.

  1. First observedv1.0.0

TDQS

A4.9/5.0
Behavior5/5

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

Discloses external RapidAPI dependency, caller-provided key requirements, billing/quota consumption, retry and fallback behavior, and the fact that each destination/date combination is a billed request. This goes beyond the read-only annotation and gives accurate expectations of side effects.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is thorough but somewhat long, with some details repeated across paragraphs and parameter descriptions. However, the content is organized into clear topical paragraphs and nearly every sentence carries practical guidance, making the length justified overall.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Covers external API integration, authentication, billing, fallback source switching, result composition, and the meaning of api_usage and by_destination. Given the tool's complexity and external dependencies, the description contains all necessary context for correct invocation and interpretation.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters5/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Every schema parameter has a meaningful description, and the description adds important semantic details such as single-origin refusal, accepted destination formats, nights vs return_date exclusivity, and even sampling behavior for max_searches. The prose supplements the schema rather than merely repeating it.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

Clearly identifies the tool as a round-trip flight fare search reading live prices from Google Flights and pricing paired legs, not separate one-ways. This distinguishes it from the sibling one-way search tool without ambiguity.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines5/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly directs use for any return-trip fare question and gives concrete guidance for flexible date ranges, multi-destination searches, and quota control via max_searches. The instructions about return_date vs nights and fallback behavior leave little room for misuse.

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