diff --git a/CHANGES.txt b/CHANGES.txt
index c195d65179..07e23c0e4b 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -1,4 +1,5 @@
 5.0.5
+ * Do not source cassandra-env.sh unnecessarily in nodetool and other tooling (CASSANDRA-20745)
  * Make source distribution buildable by ant artifacts as doc/scripts/process-native-protocol-specs-in-docker.sh was not executable (CASSANDRA-20802)
  * Fix StorageService JMX mbean not available during bootstrap (CASSANDRA-19902)
  * SSTableIndexWriter#abort() should log more quietly in cases where an exception is not provided (CASSANDRA-20695)
diff --git a/bin/nodetool b/bin/nodetool
index f78b02e344..96954c8727 100755
--- a/bin/nodetool
+++ b/bin/nodetool
@@ -43,13 +43,19 @@ if [ -z "$CASSANDRA_CONF" -o -z "$CLASSPATH" ]; then
     exit 1
 fi
 
-# Run cassandra-env.sh to pick up JMX_PORT
+JMX_PORT=""
+
+# Try to parse port from cassandra-env.sh without sourcing it
 if [ -f "$CASSANDRA_CONF/cassandra-env.sh" ]; then
-    JVM_OPTS_SAVE=$JVM_OPTS
-    MAX_HEAP_SIZE_SAVE=$MAX_HEAP_SIZE
-    . "$CASSANDRA_CONF/cassandra-env.sh"
-    MAX_HEAP_SIZE=$MAX_HEAP_SIZE_SAVE
-    JVM_OPTS="$JVM_OPTS_SAVE"
+    jmx_port_property=$(grep "^JMX_PORT=\"[0-9]\+\"$" "$CASSANDRA_CONF/cassandra-env.sh")
+    if [ ! "x${jmx_port_property}" = "x" ]; then
+        JMX_PORT=$(echo "${jmx_port_property}" | sed s/\"//g | cut -d "=" -f2)
+    fi
+fi
+
+# If, by any chance, it is not there, set it to default.
+if [ "x$JMX_PORT" = "x" ]; then
+    JMX_PORT=7199
 fi
 
 # JMX Port passed via cmd line args (-p 9999 / --port 9999 / --port=9999)
@@ -98,6 +104,11 @@ if [ "x$MAX_HEAP_SIZE" = "x" ]; then
     MAX_HEAP_SIZE="128m"
 fi
 
+# Sets the path where logback and GC logs are written.
+if [ "x$CASSANDRA_LOG_DIR" = "x" ] ; then
+    CASSANDRA_LOG_DIR="$CASSANDRA_HOME/logs"
+fi
+
 CMD=$(echo "$JAVA" $JAVA_AGENT -ea -cp "$CLASSPATH" $JVM_OPTS -Xmx$MAX_HEAP_SIZE \
             -XX:ParallelGCThreads=1 \
             -Dcassandra.storagedir="$cassandra_storagedir" \
diff --git a/tools/bin/fqltool b/tools/bin/fqltool
index dc49e50246..dd4a395615 100755
--- a/tools/bin/fqltool
+++ b/tools/bin/fqltool
@@ -37,17 +37,6 @@ if [ -z "$CASSANDRA_CONF" -o -z "$CLASSPATH" ]; then
     exit 1
 fi
 
-# Run cassandra-env.sh to pick up JMX_PORT
-if [ -f "$CASSANDRA_CONF/cassandra-env.sh" ]; then
-    JVM_OPTS_SAVE=$JVM_OPTS
-    MAX_HEAP_SIZE_SAVE=$MAX_HEAP_SIZE
-    . "$CASSANDRA_CONF/cassandra-env.sh"
-    MAX_HEAP_SIZE=$MAX_HEAP_SIZE_SAVE
-    JVM_OPTS=$JVM_OPTS_SAVE
-fi
-
-# JMX Port passed via cmd line args (-p 9999 / --port 9999 / --port=9999)
-# should override the value from cassandra-env.sh
 ARGS=""
 JVM_ARGS=""
 while true
diff --git a/tools/bin/jmxtool b/tools/bin/jmxtool
index b46305c08f..b2372c2db5 100755
--- a/tools/bin/jmxtool
+++ b/tools/bin/jmxtool
@@ -37,17 +37,6 @@ if [ -z "$CASSANDRA_CONF" -o -z "$CLASSPATH" ]; then
     exit 1
 fi
 
-# Run cassandra-env.sh to pick up JMX_PORT
-if [ -f "$CASSANDRA_CONF/cassandra-env.sh" ]; then
-    JVM_OPTS_SAVE=$JVM_OPTS
-    MAX_HEAP_SIZE_SAVE=$MAX_HEAP_SIZE
-    . "$CASSANDRA_CONF/cassandra-env.sh"
-    MAX_HEAP_SIZE=$MAX_HEAP_SIZE_SAVE
-    JVM_OPTS=$JVM_OPTS_SAVE
-fi
-
-# JMX Port passed via cmd line args (-p 9999 / --port 9999 / --port=9999)
-# should override the value from cassandra-env.sh
 ARGS=""
 JVM_ARGS=""
 while true