Larsen said the tour presented a good opportunity for Patel, who will join Todd Astle and Ish Sodhi as a front-line spinner in the 15-strong Test squad.
"Ajaz has deserved his inclusion on the sheer weight of his domestic first-class form over the past couple of summers," said Larsen.
"With Mitch Santner not fully recovered yet from his knee surgery, it's nice to have both wrist (Astle and Sodhi) and finger (Patel) spin options, given the likely conditions in the UAE."
The selectors opted to include a second wicket-keeper in Tom Blundell alongside BJ Watling in the Test squad.
Watling has also been selected in the ODI squad to play three matches against Pakistan, with two players to be added later – either from the T20 or the NZ A sections of the tour.
The Black Caps T20 squad will also draw on two further players from NZ A, one of whom will replace front-line paceman Trent Boult, who will be on paternity leave.
Boult will join the tour for the ODI and Test series.
The NZ A squad will feature first-time selections for Patel, pace bowlers Kyle Jamieson and Blair Tickner, and NZ Under 19 representative, Rachin Ravindra.
Tim Seifert, Mark Chapman and Lockie Ferguson will play the T20s for NZ A before moving into the Black Caps' T20 camp.
Larsen said with NZC placing a bigger emphasis on the "A" programme, it was an exciting time for the country's emerging players, and an excellent opportunity to develop and expand their capabilities.
"This is a great opportunity for us to expose our emerging players to foreign conditions and help develop and expand their games," he said.
"Given India A will also be visiting New Zealand over the summer, there is a lot to play for."
BLACKCAPS T20 Squad
Kane Williamson (c)
Mark Chapman
Colin de Grandhomme
Lockie Ferguson
Martin Guptill
Adam Milne
Colin Munro
Seth Rance
Tim Seifert
Ish Sodhi
Tim Southee
Ross Taylor
Two to be added from NZ A
BLACKCAPS ODI Squad
Kane Williamson (c)
Todd Astle
Trent Boult
Colin de Grandhomme
Martin Guptill
Matt Henry
Tom Latham
Colin Munro
Henry Nicholls
Ish Sodhi
Tim Southee
Ross Taylor
BJ Watling
Two to be added from NZA/BC T20 Squads
BLACKCAPS Test Squad
Kane Williamson (c)
Todd Astle
Tom Blundell
Trent Boult
Colin de Grandhomme
Matt Henry
Tom Latham
Henry Nicholls
Ajaz Patel
Jeet Raval
Ish Sodhi
Tim Southee
Ross Taylor
Neil Wagner
BJ Watling
NZ A Squad
Corey Anderson
Todd Astle (T20s, One-Day, and first FC match)
Tom Blundell
Tom Bruce
Mark Chapman (T20 only)
Lockie Ferguson (T20 only)
Kyle Jamieson
Scott Kuggeleijn
Ajaz Patel
Glenn Phillips (T20 and One-Day)
Jeet Raval (FC matches)
Rachin Ravindra
Tim Seifert (T20 and second FC match)
Blair Tickner
Logan van Beek (One-Day and FC matches)
George Worker
Will Young
Neil Wagner (Second FC match)
BJ Watling (One-Day and first FC match)