Interesting you ask this. As a matter of practice writing macros I have started adding to tiddlers fields the following where a macro is defined
Field macro-macroname with the value containing the parameters in an example of using the macro.
We could also document the use of a macro with a field macrouse-macroname. The field value could document special use cases.
It is somewhat manual to do this however it could help while designing. You could also enhance a search to also create such fields when the macro is found.
I am tempted to document others macros this way. We can then use a field filter like has:field[macro-macroname] to locate there definition and parameters. Or use prefix[macrouse-macroname] to locate tiddlers using the macro.
Just some thoughts
Tony