Add description to card metadata

README.md

@@ -1,6 +1,6 @@
 ---
 title: Precision
-emoji: 🤗 
+emoji: 🤗
 colorFrom: blue
 colorTo: red
 sdk: gradio
@@ -8,10 +8,18 @@ sdk_version: 3.0.2
 app_file: app.py
 pinned: false
 tags:
-- evaluate
-- metric
----
+  - evaluate
+  - metric
+description: >-
+  Precision is the fraction of correctly labeled positive examples out of all of
+  the examples that were labeled as positive. It is computed via the equation:
+
+  Precision = TP / (TP + FP)
 
+  where TP is the True positives (i.e. the examples correctly labeled as
+  positive) and FP is the False positive examples (i.e. the examples incorrectly
+  labeled as positive).
+---
 # Metric Card for Precision