SYMPTOM:
In a Report Services document in Strategy, when adding a prompt autotext for SAP BW variable, additional information along with prompt value is displayed, as shown in the image below:

CAUSE:
This is working as per the current design.
ACTION:
Create the MDX report against SAP BW basic InfoCube, create prompt from Strategy Developer rather than using SAP variable prompt and the autotext in Report Services document will be rendered as desired without additional information.