Do NOT short the leads to "test" a breaker! You may or may not have a
functionally, to-spec breaker after that! Just in case the idea sounded
good to you g.

Pop`

I disagreee with the idea shorting a breaker either intentially or
accidently can damage a breaker......

I used to fix office macxhines at Westinghouse Beaver, a plant that
produced circuit breakers of all sizes.

spent a LOT of time there and made friends, at one point they offered
me a job, no interview necessary. just drop application with gorgeous
secretary, give notice to current employer start in 2 weeks. it was a
fascinating place.

they cycled breakers thru hundreds of dead shorts and other hard tests.
then tore them aart to see what failed.

some dead shorts arent a problem for a breaker, its part of normal
operation.

just like turning on a lamp is.........

given all this i would not makew a habit of it..........

but dangerous to the breaker thats like saying slamming on the brakes
of a car make it less likely to stop the next time