Yes, yes, the Fan Service is Strong with this one...
Back to the story.
Yes, there is a story.
Methinks they actually do want agents with this attitude; otherwise they wouldn't have gone to all that effort to "recruit" him.
It's just... they'd really like them to be capable of pulling it off.
So that they lose fewer agents, not more.
Which is why they don't go out of their way to "encourage" such behaviours.
Especially since it's obvious that he'll dive in without enough time for anyone to think that he's actually thought everything out, so he's really got to be the best of the best at improvising.
Now, in regard to that outfit...
We've yet to see if she actually wears that when on a mission, or if it's just what she likes to wear while hanging out.
(And, yes, she was hanging out...)
It could also be psychological warfare...
The men will drool, while the women will mutter about "useless bags of meat" while looking daggers in her direction...
And in both cases be less effective than otherwise.