An indentation tool includes an installation axis, a radially oriented indentation axis, and a defined reserved space for an indentation site of a cylindrically-shaped structure, as well as a base for installing onto the structure, and an elongate punch for indenting it at its indentation site. The reserved space is spaced apart from the installation axis, and has the indentation axis passing through it. The base extends along the installation axis, and is configured for coaxial installation onto the structure, whereby its indentation site occupies the reserved space. The punch is spaced apart from the installation axis, and is supported by the base for movement along the indentation axis between a home position, in which the punch vacates the reserved space, and an indentation position, in which the punch, leading with an indentation tip, reaches into the reserved space to indent the structure at its indentation site.