There is no Crop tool in InDesign. Are you sure that's the program you're asking about? Or maybe you're thinking the name of the tool in question (whatever it is) is the Crop tool, and it's not. The Selection tool (top-most, black arrow/arrowhead tool) does all the cropping.
Each tool has a shortcut key. You may have pressed a shortcut for one of the tool's alternates, which you can reveal by pressing and holding on the tool's slot in the Tools panel, as I'm doing below. You may have typed a "K" (when not editing text) which InDesign interpreted as "Choose the Measure tool."
Resetting the workspace doesn't reset the default active tools, which is strange. You might try restarting InDesign.
There used to be a cropping tool.
Frustrating to have to relearn things that were there for years and now, poof! Too bad.
OOOOOh. Apologies. My brain was in photoshop. I will never complain again.
I'll make a wild guess that you are using Photoshop and not InDesign? If so, Photoshop changes the tool display when you change workspaces (InDesign does not). You can either return to the Essentials workspace, or reset the tool display. Both options are outlined in this post: https://www.rockymountaintraining.com/adobe-photoshop-cant-find-tool/
I have an ID CC online subscription. I have just noticed that the eyedropper tool is missing from the Tool's icons at the left of screen. How do I get it back? Cannot find a relevant post with an answer I can understand, to a simple question? Thanks
Will the keyboard shortcut work that you can see in AnneMarie's screenshot?
What's your version of InDesign?
( ACP )