ok, I still did not understand that. Just in case, I ran the program to see if it worked. Lo and behold, it doesn't. I'm guessing you're asking for help getting your program to run.

First, I added error checking.

#!/usr/bin/perl -w
use strict;
use Image::Magick;
my $text = 'test';
my $im = new Image::Magick;
$im->Read("meteo.jpg");
my $rv = $im->Annotate(
   text   => $text,
   x      => 10,
   y      => 10,
);
die("Unable to annotate image: $rv\n") if "$rv";
print "Content-type: image/jpeg\n\n"; 
binmode STDOUT;
print $im->Write('jpeg:-');
[download]

It gives me the error

Unable to annotate image: Warning 315: no delegates configuration file
+ found (delegates.mgk) [No such file or directory]
[download]

I have no idea what that means, but I suspected from the start that you might have to specify a font or family. I found an example which specified font => 'kai.ttf', so I tried font => 'Arial.ttf' which gave a promising error message:

Unable to annotate image: Warning 315: Unable to read font (Arial.ttf)
+ [No such file or directory]
[download]

Specifying the full path worked.

#!/usr/bin/perl -w
use strict;
use Image::Magick;
my $text = 'test';
my $im = new Image::Magick;
$im->Read("meteo.jpg");
my $rv = $im->Annotate(
   text   => $text,
   font   => 'C:\\WINDOWS\\Fonts\\Arial.ttf',
   x      => 10,
   y      => 10,
);
die("Unable to annotate image: $rv\n") if "$rv";
print "Content-type: image/jpeg\n\n"; 
binmode STDOUT;
print $im->Write('jpeg:-');
[download]