- If they're instructions/commands, they should likely be in the imperative form (i.e. "<You have to> Deconstruct X buildings <to get this>").
- If they're awards for having done something then they should be in past tense (i.e. "<You have> Deconstructed X buildings <to get this>").
To avoid this confusion, I suggest the developers make 2 forms of the achievement, one for when it's still not done (sounds like an instruction) and one for when it's already earned (sounds like an award; this will appear on Steam/GoG/...).
On a side note, for those of you who think that there should only be 1 option, please also give your opinion on the following matter: there's the issue of infinitive (to verb) vs. imperative (verb!) in some non-English languages for the instruction/command variant, roughly:
- "<You> Deconstruct X buildings<!>"
- "To deconstruct X buildings" (can be understood as "<Awarded for the> deconstruction of X buildings")