add legend in the help

skore/src/skore/sklearn/_estimator/base.py

@@ -2,7 +2,7 @@
 from io import StringIO
 
 import joblib
-from rich.console import Console
+from rich.console import Console, Group
 from rich.panel import Panel
 from rich.tree import Tree
 
@@ -42,10 +42,22 @@ def _get_method_description(self, method):
             else "No description available"
         )
 
+    def _get_help_legend(self):
+        """Get the help legend."""
+        return None
+
     def _create_help_panel(self):
         """Create the help panel."""
+        if self._get_help_legend():
+            content = Group(
+                self._create_help_tree(),
+                f"\n\nLegend:\n{self._get_help_legend()}",
+            )
+        else:
+            content = self._create_help_tree()
+
         return Panel(
-            self._create_help_tree(),
+            content,
             title=self._get_help_panel_title(),
             expand=False,
             border_style="orange1",

skore/src/skore/sklearn/_estimator/metrics_accessor.py

@@ -812,6 +812,11 @@ def _create_help_tree(self):
     def _get_help_panel_title(self):
         return f"[bold cyan]{self._icon} Available metrics methods[/bold cyan]"
 
+    def _get_help_legend(self):
+        return (
+            "[cyan](↗︎)[/cyan] higher is better [orange1](↘︎)[/orange1] lower is better"
+        )
+
     def _get_help_tree_title(self):
         return "[bold cyan]reporter.metrics[/bold cyan]"
 

skore/src/skore/sklearn/_estimator/report.py

@@ -321,7 +321,12 @@ def _get_cached_response_values(
     def _get_help_panel_title(self):
         return (
             f"[bold cyan]📓 Tools to diagnose estimator "
-            "{self.estimator_name}[/bold cyan]"
+            f"{self.estimator_name}[/bold cyan]"
+        )
+
+    def _get_help_legend(self):
+        return (
+            "[cyan](↗︎)[/cyan] higher is better [orange1](↘︎)[/orange1] lower is better"
         )
 
     def _create_help_tree(self):