Effective

adj.capableprofessional

What it means

Successful at producing the result that was intended.

Reach for it when judging an approach by what it actually accomplishes

The most effective reminder arrived one day before the appointment.

playful
does the trick
when an adequate practical fix deserves informal approval
not when The idiom understates rigorous evidence and may imply a temporary workaround.
everyday
successful
when the desired outcome has clearly been achieved
not when Success can depend on luck, whereas effective usually credits the chosen method.
warm
powerful
when strong impact matters more than measurable completion
not when Powerful may describe emotion or force even when it changes nothing.
professional
efficient
when results come with little waste
not when Efficiency is about resource use; an efficient process can pursue the wrong result.
professional
impactful
when noticeable influence is the intended praise
not when Impact alone can be negative or unintended, so it is less exact than effective.
formal
potent
when a concentrated agent has a strong effect
not when Potent suits medicines and influences but sounds unnatural for ordinary procedures.
literary
compelling
when an argument succeeds by holding belief or attention
not when A compelling message may persuade while failing to produce the wider desired outcome.

effective solution
The effective solution protected the seedlings without harming insects.
highly effective
A highly effective filter removed the sediment in one pass.
effective communication
Effective communication gave every household a clear evacuation route.

The definition and the example on this page are written here. The dictionaries above ground which meaning is being described, not the wording.