How to generate a completable enum field description from .proto file?

I attempt to generate a openapi.yaml like this，(just an example)
```yaml
parameters:
- name: weather
schema:
type: integer
format: int32
enum:
- 1
- 2
- 3
x-enum-descriptions:
- 'Blue sky'
- 'Slightly overcast'
- 'Take an umbrella with you'
```
But I only got
```yaml
parameters:
- name: weather
schema:
type: integer
format: enum
```
or
```yaml
parameters:
- name: weather
schema:
type: string
format: enum
enum:
- BLUE_SKY
- XXXXX
- YYYY
```

I can't found any openapi annotation for enum type, How can I do it ?