When the smithy-build.json contains a dependency which has smithy specs packaged as json, the textDocument/definition returns the json file location. The json specs can be outputted as one liner, and even if they're not, they are hard to browse.
The textDocument/hover seem to handle json specs in a nicer way and output smithy IDL calculated on the fly, maybe something similar could be done for the textDocument/definition? For example, a local cache with smithy files that would be easy to navigate.