calculator tool is greyed out and I cannot add it to my agent

Summary:

Unable to add the calculator tool to my agent. I want to use it to summarize costs on Project

Content (please ensure you mask any confidential information):

I am using a BO to fetch the Project costs details and I want to use the calculator to summarize the costs on the Project and provide the total cost and a breakdown of the cost. When I look at the calculator, it appears in Tools but it is greyed out. How can i add it on my agent ?

Version (include the version you are using, if applicable):

DEV7 - 25D

Code Snippet (add any code snippets that support your topic, if applicable):