Using Int to interpret makes plenty of sense to me.
Communication in an unknown language.
When you attempt to communicate in a language that you are not proficient in, either verbal, written, or otherwise, choose to convey either simple, moderate, or complex ideas. As usual, the DM may modify the DC based on circumstances.
Failing the check results in a misunderstanding, which often reduces their trust in you, and may even start violence.
Simple; DC 15. Getting getting the general direction to a destination, or asking the price of an item on display, or the home of a person you have a picture of. You can not attempt Persuasion or Deception check and they will only reveal common information. It takes 3x as long as normal.
Moderate: DC 20 Multi-step directions, the home of a person based on description. Or how many pages of a book you can show on YouTube. You have disadvantage on Persuasion and Deception checks. Conversing takes 2x as long as normal.
Complex: DC 25 you converse clearly. Though it is still obvious that you are not a native speaker.
Rare language: due to their more alien origin, conversing in a rare language increases the DC by 5.