The special equals style of attribute modifier tooltip used for attack damage & attack speed is not available when attribute modifiers are added via NBT (e.g. JSON recipes).
This mod changes that.

Example

The following command gives an Iron Sword with its default modifiers overridden by identical modifiers via NBT.

give @p minecraft:iron_sword{AttributeModifiers:[{Slot:"mainhand", AttributeName:"generic.attack_damage", Name:"generic.attack_damage", Amount:5, Operation:0, UUID: [I;-885041709, 1683771192, -1533567981, -1556236849]},{Slot:"mainhand", AttributeName:"generic.attack_speed", Name:"generic.attack_speed", Amount:-2.4, Operation:0,UUID: [I;-98353636, 1098926181, -1340359474, -1752847197]}]}
The tooltip without this mod installed

The tooltip with this mod installed

 

Affected UUIDs

Attribute Name	UUID
generic.attack_damage	CB3F55D3-645C-4F38-A497-9C13A33DB5CF [I;-885041709, 1683771192, -1533567981, -1556236849]
generic.attack_speed	FA233E1C-4180-4865-B01B-BCCE9785ACA3 [I;-98353636, 1098926181, -1340359474, -1752847197]

 

When one of the UUIDs listed above is used by a modifier for the corresponding attribute, an equals style tooltip will be used. These UUIDs are the UUIDs used by the default modifiers, but a quirk of the vanilla code prevents the equals style being used for modifiers loaded from NBT. Mojang doesn’t seem to consider it a bug, but it bothered me, so I made a fix.

Note to Mod Devs

If you wish to include this fix in your own mod, you MUST use Loom’s include configuration to package this mod within your JAR. The mixin used in this mod cannot coexist with other copies of itself. I lack the resources to host a Maven, so I suggest you use JitPack.

Compatible Minecraft Versions

Modifier Tooltip Fix builds are marked with the Minecraft version they were built for, they will work for that version. However since Modifier Tooltip Fix consists only of 2 simple mixins, it is highly likely that a build is compatible with future versions of Minecraft. If the latest Modifier Tooltip Fix build does not work for the latest snapshot or release, leave a comment on this project and I will update it.