Compile Error: = Expected After Function Call

i'm trying to call a function from another one, i'm getting this error 'Compiler error: = expected' but i don't know the reason, the functions simply take some values an store them in an here is the

Dim productos(19, 3) As String
Sub agregarProducto(ByVal descripcion As String, ByVal modelo As String, _
ByVal precio As String, ByVal unidad As String)
Dim r As Integer
For r = 0 To 19
If productos(r, 0) = "" Then
productos(r, 0) = descripcion
productos(r, 1) = modelo
productos(r, 2) = precio
productos(r, 3) = unidad
End If
Next
End Sub

Sub agregarProductoTelas()
Dim descripcion, modelo, precio, unidad As String
If Selection.Column = 1 Then
descripcion = Selection. Offset(0, 0).Value
modelo = Selection.Offset(0, 0).Value
precio = Selection.Offset(0, 3).Value
unidad = Selection.Offset(0, 2).Value
agregarProducto(descripcion, modelo, precio, unidad) 'error happens right here
MsgBox (descripcion)...