Hey Ace:
I consider myself an "expert" at defending against Tool attacks.
Here are a few pointers that I use to defeat Tool attacks:
1) Be willing to commit early to Tool defenses. I mean if you see that your opponent has Tooled and/or has military high, spend some resources fast and get a military going.
2) Good rushers always get forward buildings in your land early, so walling is typically not even an option. Instead, know what the best defensive Tool units are -- Bowmen and a Watch Tower.
3) If you are still in Stone and you see Clubbers coming your way, go bone them with 5-6 villagers per clubber before the clubbers upgrade to axers with armor.
Common Tool attack units are a handful axers or a few Scouts. If you have 2-3 Archery Ranges near your woodies you will be able to defend well. Place a Watch Tower in the middle of the woodies.
This investment will take 300-450 wood for ranges, 100 food for Bowman Armor, and 50 food for the Watch Tower upgrade. Then spend the 150 stone you start with for the tower, and make 6 bowmen immediately. The Bowmen will cost 240 food and 120 wood. This TTL initial investment costs 390 food, 420-570 wood, and 150 stone. Keep making Bowmen in all ranges until you have defeated the Tool army and have your Bowmen at their military buildings killing whatever comes out.
What this defensive strategy will force your opponent to do is either stop the attack and lick his wounds, or do the stone mining upgrade and come at your Bowmen with lots of Slingers. Either way this cost should keep him in the Tool Age.
Make villagers during all of this and have them start farming. Build a strong economy and maintain a strong force of bowmen. If your opponent starts making slingers, do the stone mining upgrade, put 5 villagers on stone, and start making slingers yourself.
Have a big enough group of Bowmen/Slingers that even if he Bronzes a little faster, you can stop initial Cavalry. Once you Bronze you should have a stronger economy and be able to get an easy upper hand.
Hope this helps.
Can you survive the Blitzkrieg?