add detailed docstring for validators.py

validators.py

@@ -1,3 +1,20 @@
+"""
+A validation framework to post-process and correct agent answers.
+
+This module provides a system for validating and correcting the final answers
+generated by the AI agent. This is crucial for ensuring that the output adheres
+to the strict formatting and content requirements of benchmarks like GAIA.
+
+The framework consists of:
+-   A `Validator` abstract base class that defines a common interface for all
+    validation logic, including a `can_handle` method to determine if a
+    validator is applicable to a given task.
+-   A `ValidatorRegistry` that holds all validator instances and runs them in
+    a chain, sorted by a `priority` attribute.
+-   Several concrete validator implementations for common cleanup tasks like
+    removing trailing punctuation, correcting capitalization, extracting numbers,
+    and handling domain-specific rules (e.g., the botany question).
+"""
 import re
 from abc import ABC, abstractmethod