I want to get the description of build parameters of a Jenkins build using groovy.
I want to include this description in an email using by Email-ext plugin groovy templates.
Is there some way I can achieve this?

I want to get the description of build parameters of a Jenkins build using groovy.
I want to include this description in an email using by Email-ext plugin groovy templates.
Is there some way I can achieve this?

See Parameterized System Groovy script:
...
// get parameters
def parameters = build?.actions.find{ it instanceof ParametersAction }?.parameters
parameters.each {
println "parameter ${it.name}:"
println it.dump()
println "-" * 80
}
...
Note: Since Actionable.getActions() is deprecated allActions should be used instead of actions.
Add:
println "${it.description}"
and there you are.