diff --git a/tools/testing/memblock/tests/basic_api.c b/tools/testing/memblock/tests/basic_api.c
index fbc1ce160303..cdf112d25343 100644
--- a/tools/testing/memblock/tests/basic_api.c
+++ b/tools/testing/memblock/tests/basic_api.c
@@ -26,8 +26,8 @@ static int memblock_initialization_check(void)
 /*
  * A simple test that adds a memory block of a specified base address
  * and size to the collection of available memory regions (memblock.memory).
- * It checks if a new entry was created and if region counter and total memory
- * were correctly updated.
+ * Expect to create a new entry. The region counter and total memory get
+ * updated.
  */
 static int memblock_add_simple_check(void)
 {
@@ -55,8 +55,8 @@ static int memblock_add_simple_check(void)
 /*
  * A simple test that adds a memory block of a specified base address, size
  * NUMA node and memory flags to the collection of available memory regions.
- * It checks if the new entry, region counter and total memory size have
- * expected values.
+ * Expect to create a new entry. The region counter and total memory get
+ * updated.
  */
 static int memblock_add_node_simple_check(void)
 {
@@ -87,9 +87,15 @@ static int memblock_add_node_simple_check(void)
 
 /*
  * A test that tries to add two memory blocks that don't overlap with one
- * another. It checks if two correctly initialized entries were added to the
- * collection of available memory regions (memblock.memory) and if this
- * change was reflected in memblock.memory's total size and region counter.
+ * another:
+ *
+ *  |        +--------+        +--------+  |
+ *  |        |   r1   |        |   r2   |  |
+ *  +--------+--------+--------+--------+--+
+ *
+ * Expect to add two correctly initialized entries to the collection of
+ * available memory regions (memblock.memory). The total size and
+ * region counter fields get updated.
  */
 static int memblock_add_disjoint_check(void)
 {
@@ -125,10 +131,20 @@ static int memblock_add_disjoint_check(void)
 
 /*
  * A test that tries to add two memory blocks, where the second one overlaps
- * with the beginning of the first entry (that is r1.base < r2.base + r2.size).
- * After this, it checks if two entries are merged into one region that starts
- * at r2.base and has size of two regions minus their intersection. It also
- * verifies the reported total size of the available memory and region counter.
+ * with the beginning of the first entry (that is r1.base < r2.base + r2.size):
+ *
+ *  |    +----+----+------------+          |
+ *  |    |   r|2   |   r1       |          |
+ *  +----+----+----+------------+----------+
+ *       ^    ^
+ *       |    |
+ *       |    r1.base
+ *       |
+ *       r2.base
+ *
+ * Expect to merge the two entries into one region that starts at r2.base
+ * and has size of two regions minus their intersection. The total size of
+ * the available memory is updated, and the region counter stays the same.
  */
 static int memblock_add_overlap_top_check(void)
 {
@@ -163,11 +179,20 @@ static int memblock_add_overlap_top_check(void)
 
 /*
  * A test that tries to add two memory blocks, where the second one overlaps
- * with the end of the first entry (that is r2.base < r1.base + r1.size).
- * After this, it checks if two entries are merged into one region that starts
- * at r1.base and has size of two regions minus their intersection. It verifies
- * that memblock can still see only one entry and has a correct total size of
- * the available memory.
+ * with the end of the first entry (that is r2.base < r1.base + r1.size):
+ *
+ *  |  +--+------+----------+              |
+ *  |  |  | r1   | r2       |              |
+ *  +--+--+------+----------+--------------+
+ *     ^  ^
+ *     |  |
+ *     |  r2.base
+ *     |
+ *     r1.base
+ *
+ * Expect to merge the two entries into one region that starts at r1.base
+ * and has size of two regions minus their intersection. The total size of
+ * the available memory is updated, and the region counter stays the same.
  */
 static int memblock_add_overlap_bottom_check(void)
 {
@@ -203,9 +228,17 @@ static int memblock_add_overlap_bottom_check(void)
 /*
  * A test that tries to add two memory blocks, where the second one is
  * within the range of the first entry (that is r1.base < r2.base &&
- * r2.base + r2.size < r1.base + r1.size). It checks if two entries are merged
- * into one region that stays the same. The counter and total size of available
- * memory are expected to not be updated.
+ * r2.base + r2.size < r1.base + r1.size).
+ *
+ *  |   +-------+--+-----------------------+
+ *  |   |       |r2|      r1               |
+ *  +---+-------+--+-----------------------+
+ *      ^
+ *      |
+ *      r1.base
+ *
+ * Expect to merge two entries into one region that stays the same.
+ * The counter and total size of available memory are not updated.
  */
 static int memblock_add_within_check(void)
 {
@@ -236,8 +269,8 @@ static int memblock_add_within_check(void)
 }
 
 /*
- * A simple test that tries to add the same memory block twice. The counter
- * and total size of available memory are expected to not be updated.
+ * A simple test that tries to add the same memory block twice. Expect
+ * the counter and total size of available memory to not be updated.
  */
 static int memblock_add_twice_check(void)
 {
