is there any checks for this?

do you mean when they mouse over it in the inventory?

 

not definite but you could try

    public void addInformation(ItemStack par1ItemStack, EntityPlayer par2EntityPlayer, List par3List, boolean par4) {}

in your item class

 

looking through the GuiContainer code this gets called whenever the player mouses over the item (but possibly other places too so look out for that)

 

If you didn't mean that then please clarify.