Airfare Brain

Trip at airport

trip_at_airport

Read-onlyIdempotent

The whole trip into one airport in one answer: the flight's extras on an airline (bags, seats, fees, as true_cost) AND what car hire there really costs (Car Rental Brain's measured median per day, car only, dated). Use for 'flying to Faro with Ryanair, bags and a hire car: what will it cost?'. Car only: deposits, second-driver fees and desk cover are not included; the answer links to the airport's full car-hire report.

Input Schema

Name	Required	Description
`fare`	No	Total fare for the whole party, if known
`seat`	No	Paid seat choice: none (random seat), standard, or extra (legroom / front)
`trip`	No	one_way (default) or return: return counts each extra on both flights
`airline`	No	Airline name or IATA code (optional; without it you get car hire only)
`airport`	Yes	IATA code or name of the airport you fly INTO, e.g. 'FAO', 'Faro', 'Malaga'
`infants`	No	Under-2s on a lap (default 0)
`car_days`	No	Days of car hire (default 7)
`currency`	No	Currency of the answer: EUR (default) or GBP, as the airline publishes it
`domestic`	No	true for a flight within the US: US airlines charge different bag prices there than on international routes
`priority`	No	Priority boarding
`cabin_bag`	No	A large cabin bag for the overhead locker (the small under-seat bag is free)
`hold_bags`	No	Checked bags per person (default 1); the 2nd bag often costs more
`group_bags`	No	Checked bags shared by the whole party, fewer than the people (e.g. 1 bag between 2): priced as that many 1st bags; needs checked_bag_kg
`passengers`	No	People aged 2+ (default 1)
`checked_bag_kg`	No	Checked bag(s) per person of this weight allowance, e.g. 20 or 23; omit for none

Output Schema

Name	Required	Description	Default
`note`	No
`error`	No
`flight`	No
`airport`	No
`car_hire`	No

Schema Changelog

Changes observed during successful MCP inspections.

Changed1 schema field changedOct 29, 2026

addedInput schema / properties / group_bags

Added value: +{
+  "description": "Checked bags shared by the whole party, fewer than the people (e.g. 1 bag between 2): priced as that many 1st bags; needs checked_bag_kg",
+  "maximum": 8,
+  "minimum": 1,
+  "type": "integer"
+}

Changed1 schema field changedOct 29, 2026

addedInput schema / properties / domestic

Added value: +{
+  "description": "true for a flight within the US: US airlines charge different bag prices there than on international routes",
+  "type": "boolean"
+}

Changed9 schema fields changedOct 29, 2026

addedInput schema / properties / cabin_bag / description

Added value: +"A large cabin bag for the overhead locker (the small under-seat bag is free)"

addedInput schema / properties / checked_bag_kg / description

Added value: +"Checked bag(s) per person of this weight allowance, e.g. 20 or 23; omit for none"

addedInput schema / properties / currency / description

Added value: +"Currency of the answer: EUR (default) or GBP, as the airline publishes it"

addedInput schema / properties / hold_bags / description

Added value: +"Checked bags per person (default 1); the 2nd bag often costs more"

addedInput schema / properties / infants / description
```
Added value: +"Under-2s on a lap (default 0)"
```
addedInput schema / properties / passengers / description
```
Added value: +"People aged 2+ (default 1)"
```
addedInput schema / properties / priority / description
```
Added value: +"Priority boarding"
```

addedInput schema / properties / seat / description

Added value: +"Paid seat choice: none (random seat), standard, or extra (legroom / front)"

addedInput schema / properties / trip / description

Added value: +"one_way (default) or return: return counts each extra on both flights"

AddedOct 24, 2026

TDQS

A4.1/5.0

Behavior4/5

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

Annotations already declare readOnly/idempotent/non-destructive, so the description correctly spends its words on scope limits instead: car hire is 'car only' and excludes deposits, second-driver fees and desk cover, and the answer links to the full report. That is meaningful disclosure beyond the annotations, though it does not say how the median is dated or sampled.

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 core promise is front-loaded in the first sentence, followed by a use-case example and then the car-only caveat. It is dense and mostly earns its length, though the embedded example quote is longer than needed to convey the intent.

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

Completeness4/5

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

With 15 parameters, an output schema, and rich annotations, the description supplies what structured fields cannot: the composite nature of the answer, the optional-airline branch, and the car-hire exclusions. Only the dating/measurement basis of the car-hire figure is left unstated.

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

Parameters3/5

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

Schema description coverage is 100%, so every parameter including enums and defaults is already documented. The description adds only one semantic point (airline is optional and omitting it yields car hire only); the bag/seat/passenger semantics are left entirely to the schema, so baseline 3 applies.

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?

The description names a specific composite output: airline flight extras (bags, seats, fees as true_cost) plus measured car-hire median per day at a given airport. This is clearly distinguishable from siblings like airline_fees or true_cost, which appear to cover only one half of the calculation.

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

Usage Guidelines4/5

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

It gives a concrete triggering example ('flying to Faro with Ryanair, bags and a hire car: what will it cost?') and states the condition that drops the flight half ('without it you get car hire only'). It never names the sibling tools to use instead for flight-only or cost-only questions, so routing guidance is clear but not complete.

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

All Airfare Brain tools Inspect

Try in Browser

One endpoint for every MCP toolRayrun runs every MCP server behind one URL and holds the credentials. Each call is decided per client, tool, and argument, then recorded.ray.runAd

Glama MCP Gateway

Add one secure layer between your agents and this server.