Last modified: 2014-02-24 18:25:30 UTC
See [[Wikipedia:Village pump (technical)#In API, action=opensearch returns only 15 items instead of 100 result asked for]] (which I may have to come back and make a working link for). From my testing on multiple WMF wikis, setting limit between 15-100 returns 15 results with no error message; however, setting limit over 100 returns "limit may not be over 100 (set to 101) for users" and 15 results.
Test URL: https://en.wikipedia.org/wiki/Special:ApiSandbox#action=opensearch&format=json&search=R&limit=100&namespace=0