The most common and most likely answer to this crossword clue is the 7 letter word SOLUBLE
I've seen this crossword clue in Financial Times
S
O
L
U
B
L
E
More clues leading to the result SOLUBLE
- Note blue compound, like most acetates
- Weird globules, finally fading away — able to break down in water?
- “Sun corruptly blue”: that’s how a clue should be!
- Left wearing torn blouse? That can be explained
- This puzzle should be outrageously libellous
- Like clue, only including what’s within it, note
- Is this clue like an Alka-Seltzer?
- Only accepting half of UK invested in pound? That can be sorted out
Buddy explains!

The straight part
We know that "This puzzle should be" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case this puzzle should be = soluble.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does SOLUBLE mean?
SOLUBLE adjective- Able to be dissolved.
- Able to be solved or explained.