Clumsiness

I was wondering if there is an effective value on this mesmer spell
I was messing with it today and noticed that overall I wasnt getting the result I was planning on is there more to it than just the description?

It does exactly what it says, damage and interrupting there attack. I'd rather use something like empathy, or if I am using distortion or another dodge stance, spirit of failure. It gets slightly better if you echo it, but 10 energy for nothing more than damage and the slim chance that you will stop something like an eviscerate is not really worth it (IMO).

Yep. That's all it does: interrupt an attack with a moderate amount of damage.

As with most Mesmer spells, it doesn't function very well in isolation, but I've had a lot of success running it with Mantra of Recovery. You can stop quite a few annoying Warrior or Ranger combos simply by paying attention and applying this spell at the right time. Against a hammer Warrior, this is your best friend. Its big brother, Ineptitude, is also quite good, but often rather corner case; especially since it takes your Elite slot and doesn't really have much better damage.

Also, for only 10 energy and with a cooldown of only 10 seconds, this qualifies as "spamable" for a Mesmer...

Not a great skill by any stretch, but it's solid damage for the Illusion line. I take it at least 40% of the time when I spec into Illusion.
cmb

I use it a lot and I think its pretty good.

I usually take a few skills against warriors when I play PVE, and clumsiness along with ineptitude are usually the ones I take. While I am standing behind the lines as Mesmer, and am not currently trying to interrupt a spellcaster or deal some energy draining+damage with chaos storm or removing a hex with shatter hex, I try to help out my warriors by casting clumisness on one of the enemy warriors. It stops an attack and deals a good amount of damage in my case.

I am not a PVP buff, but I did help out once in a GvG fight as Mesmer. I found myself in a corner all alone with an enemy warrior who started to hack at me. As Mesmer I have not the best armor or physical defence against this, so I used the skills that I had equipped: managed to get clumsiness off twice and ineptitude and also healed myself in between with ether renewal. I managed to kill the warrior (or, more correctly, the warrior killed himself because of the damage my spells caused when he attacked).

Try using it on a warrior that has just switched targets, an instant before they actually strike. The Eviscerate attack chain loses its teeth without Eviscerate itself. (note that you don't even need to spec Illusion to use it this way)

Thanks that answers my questiion and helps alot