A workflow parameter will ONLY be added to the space tools Parameters screen if it has been defined with a default value in a workflow .
For example, across the workflows added to the space above there are three workflow parameters with defined default values.
If a workflow parameter is not displayed then the workflow may need to be edited to add a default value for the parameter
To edit a parameter value just choose the current value it and it will go in to edit mode.
This value will then be used in the workflow
The edited value for the parameter may only be available for use in the workflow after a transition occurs from the state in which it was changed.
See: Workflow setup
You can also delete the value, however it might cause problems if the associated workflows are still active.
When adding a space workflow, a parameter reference value may only be available for use by the workflow after a workflow process, such as a transition, occurs.
For example, the initial state should not include the use of the parameter reference value for a due date or pre-assigned reviewers for approvals to avoid blocking your workflow. Alternatively, you can choose to Initialize states when applying a space workflow.