Based on the given story, here is the evaluation of its Tragedy Degree and Comedy Degree:

1. **Tragedy Degree**:
   - The story contains elements of emotional setbacks, particularly Thomas's initial depression and Mrs. Linwood's sorrow from losing her husband.
   - There are no profound tragic events that deeply affect the characters in an intensely negative way.
   - Emotional challenges are present, but they are overcome by the characters, leading to positive growth. 

   Therefore, based on the criteria, the Tragedy Degree is best rated at moderate level.

2. **Comedy Degree**:
   - The story has heartwarming and positive moments, particularly Thomas overcoming his depression, the supportive environment at the restaurant, and the ultimate success of creating "The Marwood Catch."
   - There's no prevalent comedic aspect, but it is light-hearted and uplifting.
   - The ending is happy and emotionally delightful, showing a strong sense of contentment and belonging for Thomas.

   Hence, based on the criteria, the Comedy Degree falls in the higher range though not extremely comedic.

Considering these points, the ratings would be:

```json
{
  "TragedyDegree": 5,
  "ComedyDegree": 7
}
```
