Is your employer matches XX% of your contribution, up to 5% of salary? If that is the case, definitely at least contribute 5% to get the “free money” (employer match).
Individuals contribute 401(K)s to save for retirement and also to reduce current tax liabilities as 401(K) contributions are pre-tax and are excluded from your taxable income. If your personal finance allows, I would strongly recommend that you contribute as much as possible until you reach the annual maximum limit of $15,000.