Ctags is a programming tool used by many editors to provide code navigation.
As of 2017, one of the main implementations seems to be 'Universal Ctags' (https://ctags.io/ ) which has a primitive Tcl parser inherited from the earlier Exuberant Ctags
JMN 2017. If your source files generally use only a single namespace (which arguably they usually should) then then the simple Tcl Ctags parser probably provides 'good enough' support for jumping around your code.
If you have multiple namespaces or long namespaces - then the the tag list quickly becomes unweildy.
Without support for recognizing object oriented method declarations, the Tcl ctags implementation doesn't currently let you find your way around the code.
As ctags acts as a single repository for tag information used by many editors - it'd be great to see a more featureful Tcl parser.
see for example Atom (editor for a screenshot of how the resultant tags may be used for navigation.