diff --git a/bin/pt-align b/bin/pt-align
index 249ba9b5..d544058b 100755
--- a/bin/pt-align
+++ b/bin/pt-align
@@ -1213,6 +1213,9 @@ is easier to read.
 
 =head1 OPTIONS
 
+This tool accepts additional command-line arguments.  Refer to the
+L<"SYNOPSIS"> and usage information for details.
+
 =over
 
 =item --help
diff --git a/bin/pt-stalk b/bin/pt-stalk
index da84995b..5f59ea3b 100755
--- a/bin/pt-stalk
+++ b/bin/pt-stalk
@@ -1255,7 +1255,7 @@ stalk() {
             cycles_true=0
          fi
 
-         local msg="Check results: $OPT_VARIABLE=$value, matched=${matched:-no}, cycles_true=$cycles_true"
+         local msg="Check results: $OPT_FUNCTION($OPT_VARIABLE)=$value, matched=${matched:-no}, cycles_true=$cycles_true"
          if [ "$matched" ]; then
             log "$msg"
          else
@@ -1936,6 +1936,10 @@ Plugins can stop the tool by setting the global variable C<OKTORUN>
 to C<1>.  In this case, the global variable C<EXIT_REASON> should also
 be set to indicate why the tool was stopped.
 
+Plugin writers should keep in mind that the file destination prefix currently
+in use should be accessed through the C<$prefix> variable, rather than
+C<$OPT_PREFIX>.
+
 =item --port
 
 short form: -P; type: int
diff --git a/t/pt-stalk/pt-stalk.t b/t/pt-stalk/pt-stalk.t
index b5f5e85d..7373ffbd 100644
--- a/t/pt-stalk/pt-stalk.t
+++ b/t/pt-stalk/pt-stalk.t
@@ -120,7 +120,7 @@ PerconaTest::kill_program(pid_file => $pid_file);
 $output = `cat $log_file 2>/dev/null`;
 unlike(
    $output,
-   qr/Check results: Threads_running=\d+, matched=no, cycles_true=0/,
+   qr/Check results: status\(Threads_running\)=\d+, matched=no, cycles_true=0/,
    "Non-matching results not logged because --verbose=2"
 ) or diag(`cat $log_file 2>/dev/null`, `cat $dest/*-output 2>/dev/null`);
 
@@ -153,7 +153,7 @@ PerconaTest::kill_program(pid_file => $pid_file);
 $output = `cat $log_file 2>/dev/null`;
 like(
    $output,
-   qr/Check results: Threads_running=\d+, matched=no, cycles_true=0/,
+   qr/Check results: status\(Threads_running\)=\d+, matched=no, cycles_true=0/,
    "Matching results logged with --verbose 3"
 ) or diag(`cat $dest/*-output 2>/dev/null`);
 
@@ -201,7 +201,7 @@ PerconaTest::wait_until(sub { !-f $pid_file });
 $output = `cat $dest/*-trigger 2>/dev/null`;
 like(
    $output,
-   qr/Check results: Uptime=\d+, matched=yes, cycles_true=2/,
+   qr/Check results: status\(Uptime\)=\d+, matched=yes, cycles_true=2/,
    "Collect triggered"
 )
 or diag(
@@ -304,7 +304,7 @@ is(
 $output = `cat $log_file 2>/dev/null`;
 like(
    $output,
-   qr/Check results: Aborted_connects=|variable=Aborted_connects/,
+   qr/Check results: status\(Aborted_connects\)=|variable=Aborted_connects/,
    "Read default config file"
 );