Basically, the most efficient piece of equipment for the task at hand. People who fix things for a living generally are firm believers in this concept, becuase it saves time, money and potential damage.

If you have a mechanic who uses a hammer way too much, they're not using the right tool for the job. A sysadmin who just reboots or reinstalls systems blindly without trying to figure out what is going on is also not using the right tool for the job. Using ADA when perl would do is also not using the right tool for the job.

Using a butterknife to screw on the connectors for the rabbit ears is not using the right tool for the job.

Using pliers when you really need a wrench is not using the right tool for the job.

Using an adjustable wrench when you really need a fixed wrench is not using the right tool for the job.

Using scissors when you should use wire cutters is not using the right tool for the job.