add command crontab:list

[colorcube]

... which lists the available taskIdentifier with title (description)

Otherwise you have to search your config for calling

crontab:execute <taskIdentifier>

[colorcube]

it might be handy to get the full config too for following reasons

you might want to know which command is actually called because it could be configured with '--quiet'.
Executing the task from the command line gives you no feedback. Listing the config gives you the choice to execute the original command to see the output.

[helhum]

does typo3cms configuration:showlocal EXTCONF/crontab help you out for what you need?

[colorcube]

very well Mr Hummel
indeed!