The phrase "tame effort" means exerting minimal or little energy or force to complete a task. It implies that the action required was not challenging or difficult to accomplish. Full definition
Arsenal upped the tempo in the second half, and got their opener through Ozil's tame effort from the edge of the box, which Randolph parried into the net. (skysports.com)
Admittedly it was a rather tame effort which beat Joe Hart in the first half, but the ex-Saints man showed there was nothing strange about his footwork, as he pulled off a fine piece of skill to find Roberto Firmino, who subsequently assisted James Milner for goal number two. (squawka.com)
But equally recent weeks have seen the worrying return of his difficulties getting down quickly at his near post, with both Yannick Bolasie and Kevin De Bruyne stealing crucial points from Arsenal with tame efforts. (standard.co.uk)