Robin McBryde’s 32-man touring party, which will be captained by 91-cap centre Jamie Roberts, face clashes with the Pacific Islanders in June.
The Wales interim head coach will be joined by Edwards, Wales Sevens coach Gareth Williams and regional coaches Stephen Jones and Matt Sherratt.
Edwards said: “I was having a think about how tough a tour this would be.
“If we manage to pull off two victories with 17 or 18 of our top internationals missing, it would be as good an achievement as I’ve ever achieved with Wales.”
Edwards has helped Wales to a World Cup semi-final and unprecedented Grand Slam and Six Nations title success, so the former Wigan man knows what it takes to succeed at the highest level.
He knows full well the threat Tonga and Samoa will pose given that 12 of Wales’ best players will be facing the All Blacks as part of Warren Gatland’s British & Irish Lions squad.
“Probably one of the toughest games I’ve ever been involved in was the 2011 World Cup match against Samoa,” Edwards added.
“It was a really tough game and we were lucky to come away as victors. The next time we played them they beat us and we had a full team out.
“So if we go over there, playing them on their own ground, and we can manage to pull it off it will be as good an achievement as I’ve ever managed in coaching.”
Wales’ squad includes 13 uncapped players including Rhun Williams, Seb Davies and Adam Beard.
Those young players are complimented by the likes of Roberts, Scott Williams, Samson Lee and Rob Evans who all have international experience.
Edwards is looking forward to working with some new faces.
He said: “We normally bring the young players in first to get used to the environment and the training intensity and what’s expected when you are training for Wales.
“The fact that some have gone through that process is a big help. The next step is training and playing a game and performing.”
On the tough challenges of Tonga and Samoa, Edwards added: “It’s important we don’t try to take them on at their own game.
“There are certain aspects of the game that we excel at as well, so we need to put our game on them.”
