With Mix'n'Match it would be very easy for people to help connect tools to their existing Wikidata Items or create new Wikidata Items where applicable. This would help to increase the statements linking from Wikidata Items to Toolhub entries. This data can then also be queried to fill in the missing Item IDs in Toolhub.
The import of a new catalog can be done at https://mix-n-match.toolforge.org/#/import/ and https://meta.wikimedia.org/wiki/Mix%27n%27match/Import is the manual for how to create a new catalog for uploading.