This can be queried via srd_decoder_doc_get() and should be shown somewhere for each PD (infobox, tooltip, whatever) so that users of that PD are made aware of how it works, what it supports, what quirks to expect, what limitations there are etc. etc. For reference, in sigrok-cli this is shown as part of the "-P <pd> --show" output.
Fixed in c2b80ad9a17caef1089848134b2354c544ea1dc3, thanks!