diff --git a/tests/lib/c_lib/common/src/main.c b/tests/lib/c_lib/common/src/main.c
index 693e0cfd73e..f5379d54584 100644
--- a/tests/lib/c_lib/common/src/main.c
+++ b/tests/lib/c_lib/common/src/main.c
@@ -65,17 +65,17 @@ volatile long long_max = LONG_MAX;
 volatile long long_one = 1L;
 
 /**
- *
  * @brief Test implementation-defined constants library
- * @defgroup libc_api
+ * @defgroup libc_api C Library APIs
  * @ingroup all_tests
  * @{
  *
  */
-
+/**
+ * @brief Test c library limits
+ */
 ZTEST(libc_common, test_limits)
 {
-
 	zassert_true((long_max + long_one == LONG_MIN));
 }
 
@@ -84,13 +84,15 @@ static ssize_t foobar(void)
 	return -1;
 }
 
+/**
+ * @brief Test C library ssize_t
+ */
 ZTEST(libc_common, test_ssize_t)
 {
 	zassert_true(foobar() < 0);
 }
 
 /**
- *
  * @brief Test boolean types and values library
  *
  */
@@ -110,7 +112,6 @@ volatile long long_variable;
 volatile size_t size_of_long_variable = sizeof(long_variable);
 
 /**
- *
  * @brief Test standard type definitions library
  *
  */
@@ -132,7 +133,6 @@ volatile uint8_t unsigned_byte = 0xff;
 volatile uint32_t unsigned_int = 0xffffff00;
 
 /**
- *
  * @brief Test integer types library
  *
  */
@@ -157,7 +157,6 @@ ZTEST(libc_common, test_stdint)
 }
 
 /**
- *
  * @brief Test time_t to make sure it is at least 64 bits
  *
  */
@@ -179,7 +178,6 @@ ZTEST(libc_common, test_time_t)
 char buffer[BUFSIZE];
 
 /**
- *
  * @brief Test string memset
  *
  */
@@ -199,7 +197,6 @@ ZTEST(libc_common, test_memset)
 }
 
 /**
- *
  * @brief Test string length function
  *
  * @see strlen(), strnlen().
@@ -216,7 +213,6 @@ ZTEST(libc_common, test_strlen)
 }
 
 /**
- *
  * @brief Test string compare function
  *
  * @see strcmp(), strncasecmp().
@@ -669,7 +665,7 @@ ZTEST(libc_common, test_str_operate)
  *
  * @brief test strtol function
  *
- * @detail   in 32bit system:
+ * @details   in 32bit system:
  *	when base is 10, [-2147483648..2147483647]
  *		   in 64bit system:
  *	when base is 10,
@@ -1330,3 +1326,6 @@ ZTEST(libc_common, test_exit)
 	zassert_equal(a, 0, "exit failed");
 #endif
 }
+/**
+ * @}
+ */
diff --git a/tests/lib/mem_alloc/src/main.c b/tests/lib/mem_alloc/src/main.c
index 9cabe436733..d9ccd151a93 100644
--- a/tests/lib/mem_alloc/src/main.c
+++ b/tests/lib/mem_alloc/src/main.c
@@ -35,8 +35,7 @@ TOOLCHAIN_DISABLE_GCC_WARNING(TOOLCHAIN_WARNING_ALLOC_SIZE_LARGER_THAN)
 /**
  *
  * @brief Test implementation-defined constants library
- * @defgroup libc_api
- * @ingroup all_tests
+ * @ingroup libc_api
  * @{
  *
  */
@@ -349,10 +348,6 @@ ZTEST(c_lib_dynamic_memalloc, test_memalloc_all)
 	reloc_ptr = NULL;
 }
 
-/**
- * @}
- */
-
 /**
  *
  * @brief Test dynamic memory allocation upto maximum size
@@ -375,4 +370,8 @@ ZTEST(c_lib_dynamic_memalloc, test_memalloc_max)
 }
 #endif
 
+/**
+ * @}
+ */
+
 ZTEST_SUITE(c_lib_dynamic_memalloc, NULL, NULL, NULL, NULL, NULL);
diff --git a/tests/lib/sprintf/src/main.c b/tests/lib/sprintf/src/main.c
index d91c2d891f3..d582516a0b7 100644
--- a/tests/lib/sprintf/src/main.c
+++ b/tests/lib/sprintf/src/main.c
@@ -19,8 +19,7 @@
 /**
  *
  * @brief Test implementation-defined constants library
- * @defgroup libc_api
- * @ingroup all_tests
+ * @ingroup libc_api
  * @{
  *
  */