ineffective

adj

1. Not having the desired effect; ineffectual; otiose.
2. Lacking in ability; incompetent or inadequate.

   “Fire ants circumvented the problem of an ineffective sting by having an unusual and highly effective venom that when daubed or sprayed on other ants penetrates their waxy protective integumental barrier and kills or disables them.”

   “Their use was “impermissible not because it is unwise or ineffective, but because [federal law]^([sic]) does not allow it”, the decision explained.”