diff --git a/src/tint/reader/spirv/construct.h b/src/tint/reader/spirv/construct.h
index fbefc8fa84..eebb899e38 100644
--- a/src/tint/reader/spirv/construct.h
+++ b/src/tint/reader/spirv/construct.h
@@ -149,6 +149,7 @@ struct Construct {
   const uint32_t scope_end_pos = 0;
 };
 
+/// ConstructList is a list of Construct unique pointers.
 using ConstructList = std::vector<std::unique_ptr<Construct>>;
 
 /// Converts a construct kind to a string.
diff --git a/src/tint/reader/spirv/function.h b/src/tint/reader/spirv/function.h
index e90de21e68..1a08d089bd 100644
--- a/src/tint/reader/spirv/function.h
+++ b/src/tint/reader/spirv/function.h
@@ -175,6 +175,10 @@ struct BlockInfo {
   std::vector<uint32_t> phis_needing_state_vars;
 };
 
+/// Writes the BlockInfo to the ostream
+/// @param o the ostream
+/// @param bi the BlockInfo
+/// @returns the ostream so calls can be chained
 inline std::ostream& operator<<(std::ostream& o, const BlockInfo& bi) {
   o << "BlockInfo{"
     << " id: " << bi.id << " pos: " << bi.pos
@@ -312,6 +316,10 @@ struct DefInfo {
   SkipReason skip = SkipReason::kDontSkip;
 };
 
+/// Writes the DefInfo to the ostream
+/// @param o the ostream
+/// @param di the DefInfo
+/// @returns the ostream so calls can be chained
 inline std::ostream& operator<<(std::ostream& o, const DefInfo& di) {
   o << "DefInfo{"
     << " inst.result_id: " << di.inst.result_id()
diff --git a/src/tint/reader/spirv/parser_impl.h b/src/tint/reader/spirv/parser_impl.h
index d871452a7a..96fe99c60d 100644
--- a/src/tint/reader/spirv/parser_impl.h
+++ b/src/tint/reader/spirv/parser_impl.h
@@ -58,6 +58,8 @@ namespace tint::reader::spirv {
 /// Example:   { SpvDecorationBlock }
 /// Example:   { SpvDecorationArrayStride, 16 }
 using Decoration = std::vector<uint32_t>;
+
+/// DecorationList is a list of decorations
 using DecorationList = std::vector<Decoration>;
 
 /// An AST expression with its type.
diff --git a/src/tint/reader/spirv/parser_impl_test_helper.h b/src/tint/reader/spirv/parser_impl_test_helper.h
index 9c270301e0..31640a53ba 100644
--- a/src/tint/reader/spirv/parser_impl_test_helper.h
+++ b/src/tint/reader/spirv/parser_impl_test_helper.h
@@ -307,7 +307,8 @@ class SpvParserTestBase : public T {
   }
 };
 
-// Use this form when you don't need to template any further.
+/// SpvParserTest the the base class for SPIR-V reader unit tests.
+/// Use this form when you don't need to template any further.
 using SpvParserTest = SpvParserTestBase<::testing::Test>;
 
 }  // namespace tint::reader::spirv
diff --git a/src/tint/reader/spirv/parser_type.cc b/src/tint/reader/spirv/parser_type.cc
index 7a3c97f1f8..dbe4e14a5a 100644
--- a/src/tint/reader/spirv/parser_type.cc
+++ b/src/tint/reader/spirv/parser_type.cc
@@ -119,55 +119,47 @@ struct StorageTextureHasher {
 };
 }  // namespace
 
+// Equality operators
+//! @cond Doxygen_Suppress
 static bool operator==(const Pointer& a, const Pointer& b) {
   return a.type == b.type && a.storage_class == b.storage_class;
 }
-
 static bool operator==(const Reference& a, const Reference& b) {
   return a.type == b.type && a.storage_class == b.storage_class;
 }
-
 static bool operator==(const Vector& a, const Vector& b) {
   return a.type == b.type && a.size == b.size;
 }
-
 static bool operator==(const Matrix& a, const Matrix& b) {
   return a.type == b.type && a.columns == b.columns && a.rows == b.rows;
 }
-
 static bool operator==(const Array& a, const Array& b) {
   return a.type == b.type && a.size == b.size && a.stride == b.stride;
 }
-
 static bool operator==(const Named& a, const Named& b) {
   return a.name == b.name;
 }
-
 static bool operator==(const Sampler& a, const Sampler& b) {
   return a.kind == b.kind;
 }
-
 static bool operator==(const DepthTexture& a, const DepthTexture& b) {
   return a.dims == b.dims;
 }
-
 static bool operator==(const DepthMultisampledTexture& a,
                        const DepthMultisampledTexture& b) {
   return a.dims == b.dims;
 }
-
 static bool operator==(const MultisampledTexture& a,
                        const MultisampledTexture& b) {
   return a.dims == b.dims && a.type == b.type;
 }
-
 static bool operator==(const SampledTexture& a, const SampledTexture& b) {
   return a.dims == b.dims && a.type == b.type;
 }
-
 static bool operator==(const StorageTexture& a, const StorageTexture& b) {
   return a.dims == b.dims && a.format == b.format;
 }
+//! @endcond
 
 const ast::Type* Void::Build(ProgramBuilder& b) const {
   return b.ty.void_();
diff --git a/src/tint/reader/spirv/parser_type.h b/src/tint/reader/spirv/parser_type.h
index 491b765a1e..6225a852c9 100644
--- a/src/tint/reader/spirv/parser_type.h
+++ b/src/tint/reader/spirv/parser_type.h
@@ -87,6 +87,7 @@ class Type : public Castable<Type> {
 #endif  // NDEBUG
 };
 
+/// TypeList is a list of Types
 using TypeList = std::vector<const Type*>;
 
 /// `void` type
diff --git a/src/tint/reader/spirv/usage.h b/src/tint/reader/spirv/usage.h
index df6783f456..140a4ba3ac 100644
--- a/src/tint/reader/spirv/usage.h
+++ b/src/tint/reader/spirv/usage.h
@@ -124,6 +124,10 @@ class Usage {
   bool is_storage_write_ = false;
 };
 
+/// Writes the Usage to the ostream
+/// @param out the ostream
+/// @param u the Usage
+/// @returns the ostream so calls can be chained
 inline std::ostream& operator<<(std::ostream& out, const Usage& u) {
   return u.operator<<(out);
 }
diff --git a/src/tint/writer/hlsl/generator_impl.h b/src/tint/writer/hlsl/generator_impl.h
index 4048430097..50bce98196 100644
--- a/src/tint/writer/hlsl/generator_impl.h
+++ b/src/tint/writer/hlsl/generator_impl.h
@@ -68,6 +68,7 @@ struct SanitizedResult {
 
 /// Sanitize a program in preparation for generating HLSL.
 /// @program The program to sanitize
+/// @param program the input program
 /// @param options The HLSL generator options.
 /// @returns the sanitized program and any supplementary information
 SanitizedResult Sanitize(const Program* program, const Options& options);
diff --git a/src/tint/writer/hlsl/test_helper.h b/src/tint/writer/hlsl/test_helper.h
index a75d725523..089ddb9906 100644
--- a/src/tint/writer/hlsl/test_helper.h
+++ b/src/tint/writer/hlsl/test_helper.h
@@ -105,8 +105,13 @@ class TestHelperBase : public BODY, public ProgramBuilder {
  private:
   std::unique_ptr<GeneratorImpl> gen_;
 };
+
+/// TestHelper the the base class for HLSL writer unit tests.
+/// Use this form when you don't need to template any further.
 using TestHelper = TestHelperBase<testing::Test>;
 
+/// TestParamHelper the the base class for HLSL unit tests that take a templated
+/// parameter.
 template <typename T>
 using TestParamHelper = TestHelperBase<testing::TestWithParam<T>>;