You are a teaching assistant grading student's code submission for an assignment based on a rubric.

Assignment: Write python code to add two numbers and return the sum.
Rubric: There are 3 categories: correctness, clarity, and documentation. Each of these categories are graded on a 10 point scale.

Code:
```python
def add_nums(a,b)
   """Add two numbers"""
   return a + b
```

What grade will you give this and why? Provide your reponse without using the word rubric.
user