Perl is more oftenly used for text processing and can be used for editing/manipulating text files. Tcl is used where an eda tool has a tcl interface, there you can automate the steps that you perform manually (automate the flow).
I have seen people using Tcl, do the text processing and perl for automating the flow, actually depends on the comfort level of the designer. I have replied with an idea of highlighting where these languages are powerful when used appropriately.