[Improve] Add the desc of the vars in swagger-ui

[aroundabout]

Feature Description (功能描述)

subtask of #2088, init PR: #1880

Now, in swagger-ui, we the desc of the input vars are the same with the name of vars. It may be better if we add the desc of the vars.

[zzzk1]

@imbajin hi, i want to try this

[imbajin]

@imbajin hi, i want to try this

@zzzk1 Nice, could comment here and handle it with @aroundabout, or contact me/us if need more context