It would be nice that when you look at something to harvest wether ore/wood/or fibre to know what type before you start harvesting. Right now you must start harvesting to know the type of material. Could you show where it shows the strength of tool you need also put the type of material? It would help especially with ore
When you look at a node, if there is a number, that is the required tool rating to harvest it.
For Fibre, Ore, and Wood wsually that number is 25 for T2, 50 for T3, 75 for T4.
Humbaba requires 40 on your Knife to harvest. Not sure about other Legendaries.