As we've already discovered, the needlessly short name is, in fact, a name without sufficient meaning. The needlessly long name is, therefore, a name with too much meaning. You may wonder how a name could have too much meaning. Meaning is a good thing, but too much meaning crushed into a single name can only serve to confuse; for example:

documentManager.refreshAndSaveSignedAndNonPendingDocuments();

This name is hard to understand: is it refreshing and saving documents that are signed and documents that are non-pending, or is it refreshing and saving documents that are both signed and non-pending? It's unclear.

This long name gives us a clue that the underlying abstraction is needlessly complex. We can split the name into its constituent parts to get a full grasp of its interface:

• refresh (verb): The refreshing action that occurs on a document
• save (verb): The saving action that occurs on a document
• signed (adjective): The signed state of a document
• non-pending (adjective): The non-pending state of a document
• document (noun): The document itself

We have a few different things happening here. With names this long, a good guideline is to refactor the underlying abstraction so that we only need a name with, at most, one verb, one adjective, and one noun. For example, we could take our long name and split its function into four distinct functions:

documentManager.refreshSignedDocuments();
documentManager.refreshNonPendingDocuments();
documentManager.saveSignedDocuments();
documentManager.saveNonPendingDocuments();

Alternatively, if the intent is to perform actions on documents that carry multiple states (SIGNED and NON_PENDING), then we could implement a method like this for refreshing (and a similar one for the saving action):

documentManager.refreshDocumentsWithStates([
  documentManager.STATE_SIGNED,
  documentManager.STATE_NON_PENDING
]);

The point is that long names are a clue to a broken or confused abstraction. Making a name more understandable usually goes hand in hand with making an abstraction more understandable.

As with short names, the problem is not the length of the name itself: it is what the length usually indicates. With long names, what is indicated is crushing too much meaning into a single name, indicating a confused abstraction.