rpc: Documentation fixups

test/lint/lint-rpc-help.sh

@@ -3,10 +3,17 @@
 # Copyright (c) 2018 The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
+#
+# Check that all RPC help texts are generated by RPCHelpMan.
 
 export LC_ALL=C
 
 EXIT_CODE=0
+
+# Assume that all multiline strings passed into a runtime_error are help texts.
+# This is potentially fragile, but the linter is only temporary and can safely
+# be removed early 2019.
+
 non_autogenerated_help=$(grep --perl-regexp --null-data --only-matching 'runtime_error\(\n\s*".*\\n"\n' $(git ls-files -- "*.cpp"))
 if [[ ${non_autogenerated_help} != "" ]]; then
     echo "Must use RPCHelpMan to generate the help for the following RPC methods:"