The most common and most likely answer to this crossword clue is the 7 letter word WHIPSAW
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More clues leading to the result WHIPSAW
Buddy explains!

The straight part
We know that "tool" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case tool = whipsaw.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 WHIPSAW mean?
WHIPSAW noun- A rip saw often operated by two people
- To operate a whipsaw.
- To cause (a trader) to lose potential profit by buying shares just before the price falls, or by selling them just before the price rises.
- To defeat someone in two different ways at once.
- Of a trade union: to coerce employers into capitulating by bringing them the news that other (more easily convinced) employers have already done so.
- (US politics) To accept bribes from multiple parties at once, with the intent of letting down one or more of them.
- Having the characteristic of arguing two sides at once