diff --git a/.swiftlint.yml b/.swiftlint.yml
index bf40b6c..ca9f13e 100644
--- a/.swiftlint.yml
+++ b/.swiftlint.yml
@@ -17,7 +17,7 @@ opt_in_rules:
   #- file_name
   #- file_types_order
   #- indentation_width
-  #- missing_docs
+  - missing_docs
   #- multiline_arguments_brackets
   #- multiline_literal_brackets
   #- multiline_parameters_brackets
diff --git a/Sources/FirebladeMath/Functions/radians.swift b/Sources/FirebladeMath/Functions/radians.swift
index 1f771f9..b3215be 100644
--- a/Sources/FirebladeMath/Functions/radians.swift
+++ b/Sources/FirebladeMath/Functions/radians.swift
@@ -14,6 +14,10 @@ public func radians(_ degrees: Double) -> Double {
     degrees * kDegreeToRadians64
 }
 
+/// Converts degress to radians.
+///
+/// - Parameter degrees: an angle vector (in degrees)
+/// - Returns: the argument converted to radians.
 @inline(__always)
 public func radians(_ degrees: Vec3f) -> Vec3f {
     Vec3f(x: FirebladeMath.radians(degrees.x),
diff --git a/Sources/FirebladeMath/Quat/Quat4f+Euler.swift b/Sources/FirebladeMath/Quat/Quat4f+Euler.swift
index 2043d62..14cddc6 100644
--- a/Sources/FirebladeMath/Quat/Quat4f+Euler.swift
+++ b/Sources/FirebladeMath/Quat/Quat4f+Euler.swift
@@ -12,6 +12,9 @@ extension Quat4f {
     //      return Quat4f(q1, q2, q3, q4)
     //  }
 
+    /// Creates a quaternion from Euler angles using 1-2-3 (X-Y-Z) rotation sequence.
+    /// - Parameter euler: Euler angles in radians.
+    /// - Returns: A quaternion representing the rotation.
     public static func fromEulerAngles_123(_ euler: Vec3f) -> Quat4f {
         let c1 = cos(euler.x / 2.0)
         let s1 = sin(euler.x / 2.0)
@@ -41,6 +44,9 @@ extension Quat4f {
     //     return Quat4f(q1, q2, q3, q4)
     // }
 
+    /// Creates a quaternion from Euler angles using 1-3-2 (X-Z-Y) rotation sequence.
+    /// - Parameter euler: Euler angles in radians.
+    /// - Returns: A quaternion representing the rotation.
     public static func fromEulerAngles_132(_ euler: Vec3f) -> Quat4f {
         let c1 = cos(euler.x / 2.0)
         let s1 = sin(euler.x / 2.0)
@@ -70,6 +76,9 @@ extension Quat4f {
     //      return Quat4f(q1, q2, q3, q4)
     //  }
 
+    /// Creates a quaternion from Euler angles using 2-1-3 (Y-X-Z) rotation sequence.
+    /// - Parameter euler: Euler angles in radians.
+    /// - Returns: A quaternion representing the rotation.
     public static func fromEulerAngles_213(_ euler: Vec3f) -> Quat4f {
         let c1 = cos(euler.x / 2.0)
         let s1 = sin(euler.x / 2.0)
@@ -86,6 +95,9 @@ extension Quat4f {
         return Quat4f(q1, q2, q3, q4)
     }
 
+    /// Creates a quaternion from Euler angles using 2-3-1 (Y-Z-X) rotation sequence.
+    /// - Parameter euler: Euler angles in radians.
+    /// - Returns: A quaternion representing the rotation.
     public static func fromEulerAngles_231(_ euler: Vec3f) -> Quat4f {
         let c1 = cos(euler.x / 2.0)
         let s1 = sin(euler.x / 2.0)
@@ -115,6 +127,9 @@ extension Quat4f {
     //     return Quat4f(q1, q2, q3, q4)
     // }
 
+    /// Creates a quaternion from Euler angles using 3-1-2 (Z-X-Y) rotation sequence.
+    /// - Parameter euler: Euler angles in radians.
+    /// - Returns: A quaternion representing the rotation.
     public static func fromEulerAngles_312(_ euler: Vec3f) -> Quat4f {
         let c1 = cos(euler.x / 2.0)
         let s1 = sin(euler.x / 2.0)
@@ -144,6 +159,9 @@ extension Quat4f {
     //     return Quat4f(q1, q2, q3, q4)
     // }
 
+    /// Creates a quaternion from Euler angles using 3-2-1 (Z-Y-X) rotation sequence.
+    /// - Parameter euler: Euler angles in radians.
+    /// - Returns: A quaternion representing the rotation.
     public static func fromEulerAngles_321(_ euler: Vec3f) -> Quat4f {
         let c1 = cos(euler.x / 2.0)
         let s1 = sin(euler.x / 2.0)
@@ -160,23 +178,32 @@ extension Quat4f {
         return Quat4f(q1, q2, q3, q4)
     }
 
+    /// Creates a quaternion from pitch, yaw, and roll angles in radians.
+    /// - Parameters:
+    ///   - pitch: Rotation around the X axis in radians.
+    ///   - yaw: Rotation around the Y axis in radians.
+    ///   - roll: Rotation around the Z axis in radians.
     @inlinable
     public init(pitch: Float, yaw: Float, roll: Float) {
         self = Quat4f.fromEulerAngles_321(Vec3f(pitch, yaw, roll))
     }
 
+    /// The Euler angles (pitch, yaw, roll) in radians.
     @inlinable public var eulerAngles: Vec3f {
         quaternionToEulerAngles_321(self)
     }
 
+    /// The pitch angle in radians (rotation around the X axis).
     @inlinable public var pitch: Float {
         eulerAngles.x
     }
 
+    /// The yaw angle in radians (rotation around the Y axis).
     @inlinable public var yaw: Float {
         eulerAngles.y
     }
 
+    /// The roll angle in radians (rotation around the Z axis).
     @inlinable public var roll: Float {
         eulerAngles.z
     }
@@ -208,6 +235,9 @@ extension Quat4f {
 //    return Vec3f(e1, e2, e3)
 // }
 
+/// Converts a quaternion to Euler angles using 1-2-3 (X-Y-Z) rotation sequence.
+/// - Parameter quat: The input quaternion.
+/// - Returns: The Euler angles in radians.
 public func quaternionToEulerAngles_123(_ quat: Quat4f) -> Vec3f {
     let q0 = quat.w
     let q1 = quat.z
@@ -231,6 +261,9 @@ public func quaternionToEulerAngles_123(_ quat: Quat4f) -> Vec3f {
 //    return Vec3f(e1, e2, e3)
 // }
 
+/// Converts a quaternion to Euler angles using 1-3-2 (X-Z-Y) rotation sequence.
+/// - Parameter quat: The input quaternion.
+/// - Returns: The Euler angles in radians.
 public func quaternionToEulerAngles_132(_ quat: Quat4f) -> Vec3f {
     let q0 = quat.w
     let q1 = quat.z
@@ -255,6 +288,9 @@ public func quaternionToEulerAngles_132(_ quat: Quat4f) -> Vec3f {
 //    return Vec3f(e1, e2, e3)
 // }
 
+/// Converts a quaternion to Euler angles using 2-1-3 (Y-X-Z) rotation sequence.
+/// - Parameter quat: The input quaternion.
+/// - Returns: The Euler angles in radians.
 public func quaternionToEulerAngles_213(_ quat: Quat4f) -> Vec3f {
     let q0 = quat.w
     let q1 = quat.z
@@ -268,6 +304,9 @@ public func quaternionToEulerAngles_213(_ quat: Quat4f) -> Vec3f {
     return Vec3f(e1, e2, e3)
 }
 
+/// Converts a quaternion to Euler angles using 2-3-1 (Y-Z-X) rotation sequence.
+/// - Parameter quat: The input quaternion.
+/// - Returns: The Euler angles in radians.
 public func quaternionToEulerAngles_231(_ quat: Quat4f) -> Vec3f {
     let q0 = quat.w
     let q1 = quat.z
@@ -292,6 +331,9 @@ public func quaternionToEulerAngles_231(_ quat: Quat4f) -> Vec3f {
 //    return Vec3f(e1, e2, e3)
 // }
 
+/// Converts a quaternion to Euler angles using 3-1-2 (Z-X-Y) rotation sequence.
+/// - Parameter quat: The input quaternion.
+/// - Returns: The Euler angles in radians.
 public func quaternionToEulerAngles_312(_ quat: Quat4f) -> Vec3f {
     let q0 = quat.w
     let q1 = quat.z
@@ -316,6 +358,9 @@ public func quaternionToEulerAngles_312(_ quat: Quat4f) -> Vec3f {
 //    return Vec3f(e1, e2, e3)
 // }
 
+/// Converts a quaternion to Euler angles using 3-2-1 (Z-Y-X) rotation sequence.
+/// - Parameter quat: The input quaternion.
+/// - Returns: The Euler angles in radians.
 public func quaternionToEulerAngles_321(_ quat: Quat4f) -> Vec3f {
     let q0 = quat.w
     let q1 = quat.z
diff --git a/Sources/FirebladeMath/Quat/Quaternion+Identity.swift b/Sources/FirebladeMath/Quat/Quaternion+Identity.swift
index 7493851..406bd4f 100644
--- a/Sources/FirebladeMath/Quat/Quaternion+Identity.swift
+++ b/Sources/FirebladeMath/Quat/Quaternion+Identity.swift
@@ -1,10 +1,12 @@
 extension Quat4d {
+    /// Returns the identity quaternion.
     public static var identity: Quat4d {
         Quat4d(0.0, 0.0, 0.0, 1.0)
     }
 }
 
 extension Quat4f {
+    /// Returns the identity quaternion.
     public static var identity: Quat4f {
         Quat4f(0.0, 0.0, 0.0, 1.0)
     }