(Very) Simplistic tool for trying out a OpenSearch Description file :
http://www.nearby.org.uk/opensearch/
… includes a Gmap to make defining the lat/long and/or bbox easy. (if the file has geo extensions)
(Just submit the same file again, if you update it. btw don’t submit a definition file you don’t want to become public, but remember it is called ‘open’
I realised after mentioning we updated the description file on www.geograph.org.uk, that it wasn’t fully tested, (hate testing, but not adverse to spending 2 hours scripting a tester), and in fact this tool highlighted a mistake!
Hope it of interest, feedback welcome,