diff --git a/src/libraries/System.Private.CoreLib/src/System/Half.cs b/src/libraries/System.Private.CoreLib/src/System/Half.cs
index 2e71e336928b71..9450d669ce7188 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Half.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Half.cs
@@ -340,7 +340,7 @@ public static Half Parse(ReadOnlySpan<char> s, NumberStyles style = DefaultParse
         }
 
         /// <summary>
-        /// Tries to parses a <see cref="Half"/> from a <see cref="string"/> in the default parse style.
+        /// Tries to parse a <see cref="Half"/> from a <see cref="string"/> in the default parse style.
         /// </summary>
         /// <param name="s">The input to be parsed.</param>
         /// <param name="result">The equivalent <see cref="Half"/> value representing the input string if the parse was successful. If the input exceeds Half's range, a <see cref="Half.PositiveInfinity"/> or <see cref="Half.NegativeInfinity"/> is returned. If the parse was unsuccessful, a default <see cref="Half"/> value is returned.</param>
@@ -356,7 +356,7 @@ public static bool TryParse([NotNullWhen(true)] string? s, out Half result)
         }
 
         /// <summary>
-        /// Tries to parses a <see cref="Half"/> from a <see cref="ReadOnlySpan{Char}"/> in the default parse style.
+        /// Tries to parse a <see cref="Half"/> from a <see cref="ReadOnlySpan{Char}"/> in the default parse style.
         /// </summary>
         /// <param name="s">The input to be parsed.</param>
         /// <param name="result">The equivalent <see cref="Half"/> value representing the input string if the parse was successful. If the input exceeds Half's range, a <see cref="Half.PositiveInfinity"/> or <see cref="Half.NegativeInfinity"/> is returned. If the parse was unsuccessful, a default <see cref="Half"/> value is returned.</param>
diff --git a/src/libraries/System.Private.CoreLib/src/System/IParsable.cs b/src/libraries/System.Private.CoreLib/src/System/IParsable.cs
index e2891fbd689475..f53fbec7327848 100644
--- a/src/libraries/System.Private.CoreLib/src/System/IParsable.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/IParsable.cs
@@ -19,7 +19,7 @@ public interface IParsable<TSelf>
         /// <exception cref="OverflowException"><paramref name="s" /> is not representable by <typeparamref name="TSelf" />.</exception>
         static abstract TSelf Parse(string s, IFormatProvider? provider);
 
-        /// <summary>Tries to parses a string into a value.</summary>
+        /// <summary>Tries to parse a string into a value.</summary>
         /// <param name="s">The string to parse.</param>
         /// <param name="provider">An object that provides culture-specific formatting information about <paramref name="s" />.</param>
         /// <param name="result">On return, contains the result of successfully parsing <paramref name="s" /> or an undefined value on failure.</param>
diff --git a/src/libraries/System.Private.CoreLib/src/System/ISpanParsable.cs b/src/libraries/System.Private.CoreLib/src/System/ISpanParsable.cs
index 2e24d5173e2fbd..bdc00e5331312d 100644
--- a/src/libraries/System.Private.CoreLib/src/System/ISpanParsable.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/ISpanParsable.cs
@@ -18,7 +18,7 @@ public interface ISpanParsable<TSelf> : IParsable<TSelf>
         /// <exception cref="OverflowException"><paramref name="s" /> is not representable by <typeparamref name="TSelf" />.</exception>
         static abstract TSelf Parse(ReadOnlySpan<char> s, IFormatProvider? provider);
 
-        /// <summary>Tries to parses a span of characters into a value.</summary>
+        /// <summary>Tries to parse a span of characters into a value.</summary>
         /// <param name="s">The span of characters to parse.</param>
         /// <param name="provider">An object that provides culture-specific formatting information about <paramref name="s" />.</param>
         /// <param name="result">On return, contains the result of successfully parsing <paramref name="s" /> or an undefined value on failure.</param>
diff --git a/src/libraries/System.Private.CoreLib/src/System/IntPtr.cs b/src/libraries/System.Private.CoreLib/src/System/IntPtr.cs
index bf57124154482d..27f1289a3a9025 100644
--- a/src/libraries/System.Private.CoreLib/src/System/IntPtr.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/IntPtr.cs
@@ -242,6 +242,11 @@ public static bool TryParse(ReadOnlySpan<char> s, out nint result)
             return nint_t.TryParse(s, out Unsafe.As<nint, nint_t>(ref result));
         }
 
+        /// <summary>Tries to parse a string into a value.</summary>
+        /// <param name="s">A read-only span of characters containing a number to convert.</param>
+        /// <param name="provider">An object that provides culture-specific formatting information about <paramref name="s" />.</param>
+        /// <param name="result">When this method returns, contains the result of successfully parsing <paramref name="s" /> or an undefined value on failure.</param>
+        /// <returns><see langword="true" /> if <paramref name="s" /> was converted successfully; otherwise, <see langword="false" />.</returns>
         public static bool TryParse(ReadOnlySpan<char> s, IFormatProvider? provider, out nint result)
         {
             Unsafe.SkipInit(out result);
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/INumberBase.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/INumberBase.cs
index 7bc025bf806ce0..a994dda9c2888a 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/INumberBase.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/INumberBase.cs
@@ -330,7 +330,7 @@ protected static abstract bool TryConvertToTruncating<TOther>(TSelf value, [Mayb
             where TOther : INumberBase<TOther>;
 #nullable restore
 
-        /// <summary>Tries to parses a string into a value.</summary>
+        /// <summary>Tries to parse a string into a value.</summary>
         /// <param name="s">The string to parse.</param>
         /// <param name="style">A bitwise combination of number styles that can be present in <paramref name="s" />.</param>
         /// <param name="provider">An object that provides culture-specific formatting information about <paramref name="s" />.</param>
@@ -339,7 +339,7 @@ protected static abstract bool TryConvertToTruncating<TOther>(TSelf value, [Mayb
         /// <exception cref="ArgumentException"><paramref name="style" /> is not a supported <see cref="NumberStyles" /> value.</exception>
         static abstract bool TryParse([NotNullWhen(true)] string? s, NumberStyles style, IFormatProvider? provider, out TSelf result);
 
-        /// <summary>Tries to parses a span of characters into a value.</summary>
+        /// <summary>Tries to parse a span of characters into a value.</summary>
         /// <param name="s">The span of characters to parse.</param>
         /// <param name="style">A bitwise combination of number styles that can be present in <paramref name="s" />.</param>
         /// <param name="provider">An object that provides culture-specific formatting information about <paramref name="s" />.</param>
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/Matrix3x2.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/Matrix3x2.cs
index e56e41c47984b9..f939ec9abded3a 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/Matrix3x2.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/Matrix3x2.cs
@@ -68,6 +68,15 @@ public static Matrix3x2 Identity
             get => _identity;
         }
 
+        /// <summary>Gets or sets the element at the specified indices.</summary>
+        /// <param name="row">The index of the row containing the element to get or set.</param>
+        /// <param name="column">The index of the column containing the element to get or set.</param>
+        /// <returns>The element at [<paramref name="row" />][<paramref name="column" />].</returns>
+        /// <exception cref="ArgumentOutOfRangeException">
+        /// <paramref name="row" /> was less than zero or greater than the number of rows.
+        /// -or-
+        /// <paramref name="column" /> was less than zero or greater than the number of columns.
+        /// </exception>
         public unsafe float this[int row, int column]
         {
             get
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/Matrix4x4.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/Matrix4x4.cs
index fa0aea888652d0..d0738641a3e2ec 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/Matrix4x4.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/Matrix4x4.cs
@@ -152,6 +152,15 @@ public static Matrix4x4 Identity
             get => _identity;
         }
 
+        /// <summary>Gets or sets the element at the specified indices.</summary>
+        /// <param name="row">The index of the row containing the element to get or set.</param>
+        /// <param name="column">The index of the column containing the element to get or set.</param>
+        /// <returns>The element at [<paramref name="row" />][<paramref name="column" />].</returns>
+        /// <exception cref="ArgumentOutOfRangeException">
+        /// <paramref name="row" /> was less than zero or greater than the number of rows.
+        /// -or-
+        /// <paramref name="column" /> was less than zero or greater than the number of columns.
+        /// </exception>
         public unsafe float this[int row, int column]
         {
             get
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/Quaternion.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/Quaternion.cs
index c1f21dc7b32fd0..154615379e2ac1 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/Quaternion.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/Quaternion.cs
@@ -68,6 +68,10 @@ public static Quaternion Identity
             get => new Quaternion(0, 0, 0, 1);
         }
 
+        /// <summary>Gets or sets the element at the specified index.</summary>
+        /// <param name="index">The index of the element to get or set.</param>
+        /// <returns>The element at <paramref name="index" />.</returns>
+        /// <exception cref="ArgumentOutOfRangeException"><paramref name="index" /> was less than zero or greater than the number of elements.</exception>
         public float this[int index]
         {
             get => GetElement(this, index);
@@ -98,7 +102,7 @@ private static float GetElementUnsafe(ref Quaternion quaternion, int index)
         }
 
         /// <summary>Sets the element at the specified index.</summary>
-        /// <param name="quaternion">The vector of the element to get.</param>
+        /// <param name="quaternion">The vector of the element to set.</param>
         /// <param name="index">The index of the element to set.</param>
         /// <param name="value">The value of the element to set.</param>
         /// <exception cref="ArgumentOutOfRangeException"><paramref name="index" /> was less than zero or greater than the number of elements.</exception>
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/Vector2.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/Vector2.cs
index 8556952f32b357..90e2aa683ca7bb 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/Vector2.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/Vector2.cs
@@ -86,6 +86,10 @@ public static Vector2 UnitY
             get => new Vector2(0.0f, 1.0f);
         }
 
+        /// <summary>Gets or sets the element at the specified index.</summary>
+        /// <param name="index">The index of the element to get or set.</param>
+        /// <returns>The the element at <paramref name="index" />.</returns>
+        /// <exception cref="ArgumentOutOfRangeException"><paramref name="index" /> was less than zero or greater than the number of elements.</exception>
         public float this[int index]
         {
             get => GetElement(this, index);
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/Vector3.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/Vector3.cs
index c04228da9a76fb..e800227711f594 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/Vector3.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/Vector3.cs
@@ -106,6 +106,10 @@ public static Vector3 UnitZ
             get => new Vector3(0.0f, 0.0f, 1.0f);
         }
 
+        /// <summary>Gets or sets the element at the specified index.</summary>
+        /// <param name="index">The index of the element to get or set.</param>
+        /// <returns>The the element at <paramref name="index" />.</returns>
+        /// <exception cref="ArgumentOutOfRangeException"><paramref name="index" /> was less than zero or greater than the number of elements.</exception>
         public float this[int index]
         {
             get => GetElement(this, index);
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/Vector4.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/Vector4.cs
index c0c709f1d27101..bb12c1d1cab52d 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/Vector4.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/Vector4.cs
@@ -128,6 +128,10 @@ public static Vector4 UnitW
             get => new Vector4(0.0f, 0.0f, 0.0f, 1.0f);
         }
 
+        /// <summary>Gets or sets the element at the specified index.</summary>
+        /// <param name="index">The index of the element to get or set.</param>
+        /// <returns>The the element at <paramref name="index" />.</returns>
+        /// <exception cref="ArgumentOutOfRangeException"><paramref name="index" /> was less than zero or greater than the number of elements.</exception>
         public float this[int index]
         {
             get => GetElement(this, index);
diff --git a/src/libraries/System.Private.CoreLib/src/System/Runtime/InteropServices/NFloat.cs b/src/libraries/System.Private.CoreLib/src/System/Runtime/InteropServices/NFloat.cs
index 9aeef16dadb4dd..981044c6d3c5e1 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Runtime/InteropServices/NFloat.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Runtime/InteropServices/NFloat.cs
@@ -1763,6 +1763,7 @@ private static bool TryConvertTo<TOther>(NFloat value, [MaybeNullWhen(false)] ou
         // IParsable
         //
 
+        /// <inheritdoc cref="IParsable{TSelf}.TryParse(string?, IFormatProvider?, out TSelf)" />
         public static bool TryParse([NotNullWhen(true)] string? s, IFormatProvider? provider, out NFloat result) => TryParse(s, NumberStyles.Float | NumberStyles.AllowThousands, provider, out result);
 
         //
diff --git a/src/libraries/System.Private.CoreLib/src/System/UIntPtr.cs b/src/libraries/System.Private.CoreLib/src/System/UIntPtr.cs
index b0458bf60ac528..9cce3df8fa560d 100644
--- a/src/libraries/System.Private.CoreLib/src/System/UIntPtr.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/UIntPtr.cs
@@ -219,7 +219,11 @@ public static bool TryParse([NotNullWhen(true)] string? s, out nuint result)
             return nuint_t.TryParse(s, out Unsafe.As<nuint, nuint_t>(ref result));
         }
 
-        /// <inheritdoc cref="IParsable{TSelf}.TryParse(string?, IFormatProvider?, out TSelf)" />
+        /// <summary>Tries to parse a string into a value.</summary>
+        /// <param name="s">A read-only span of characters containing a number to convert.</param>
+        /// <param name="provider">An object that provides culture-specific formatting information about <paramref name="s" />.</param>
+        /// <param name="result">When this method returns, contains the result of successfully parsing <paramref name="s" /> or an undefined value on failure.</param>
+        /// <returns><see langword="true" /> if <paramref name="s" /> was converted successfully; otherwise, <see langword="false" />.</returns>
         public static bool TryParse(ReadOnlySpan<char> s, IFormatProvider? provider, out nuint result)
         {
             Unsafe.SkipInit(out result);
@@ -238,6 +242,7 @@ public static bool TryParse(ReadOnlySpan<char> s, out nuint result)
             return nuint_t.TryParse(s, out Unsafe.As<nuint, nuint_t>(ref result));
         }
 
+        /// <inheritdoc cref="IParsable{TSelf}.TryParse(string?, IFormatProvider?, out TSelf)" />
         public static bool TryParse([NotNullWhen(true)] string? s, IFormatProvider? provider, out nuint result)
         {
             Unsafe.SkipInit(out result);
diff --git a/src/libraries/System.Runtime.Numerics/src/System/Numerics/BigInteger.cs b/src/libraries/System.Runtime.Numerics/src/System/Numerics/BigInteger.cs
index 1175591a97e005..532f12588976db 100644
--- a/src/libraries/System.Runtime.Numerics/src/System/Numerics/BigInteger.cs
+++ b/src/libraries/System.Runtime.Numerics/src/System/Numerics/BigInteger.cs
@@ -5199,6 +5199,7 @@ static bool INumberBase<BigInteger>.TryConvertToTruncating<TOther>(BigInteger va
         // IParsable
         //
 
+        /// <inheritdoc cref="IParsable{TSelf}.TryParse(string?, IFormatProvider?, out TSelf)" />
         public static bool TryParse([NotNullWhen(true)] string? s, IFormatProvider? provider, out BigInteger result) => TryParse(s, NumberStyles.Integer, provider, out result);
 
         //