Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See Parameter IDs.
Parameter: Mode
TOOL_MODE_INTERACTIONParameter: Radius
TOOL_PLACEMENT_OUTER_RADIUSParameter: Object Spacing
TOOL_EXCLUSION_RADIUSParameter: Use Splats
TOOL_USE_SPLATSParameter: Splat Spacing
TOOL_INTER_SPLAT_SEP_DISTANCEParameter: Count
TOOL_PLACEMENT_ATTEMPTS_PER_SPLATParameter: Density
TOOL_PLACEMENT_DENSITYParameter: Source
TOOL_MODE_OBJECT_SOURCEParameter: Random Order
TOOL_RANDOMIZE_ORDERParameter: Seed
TOOL_RANDOM_SEEDParameter: Align To
TOOL_MODE_ALIGN_TOParameter: Reference Point
TOOL_ALIGN_REFERENCEParameter: Position Min/Max
TOOL_MIN_MAX_Y_OFFSETParameter: Rotation Range
TOOL_ROTATION_RANGEParameter: Scale Min/Max
TOOL_MIN_MAX_SCALEParameter: Show mouse region preview
TOOL_SHOW_PREVIEW_REGIONParameter: Show Placements
TOOL_SHOW_PLACEMENTSParameter: Show Splat Regions
TOOL_SHOW_SPLAT_REGIONSParameter: End Stroke
TOOL_BUTTON_END_SESSION