"listCollections" command fails with BSONObjectTooLarge error when:
- the batch size is not specified or is large enough;
- the number of entries to return is larger than approximately 3300;
- total BSON size of entries to return approaches 16MB.
Likely other commands such as "find" and "aggregate" are affected.
Extremely likely the root cause is not accounting for array element field element size when building the result.