Tyrant (Myiozetetes similis)

I'm almost sure it is the Social Flycatcher. I can't see well the head to rule out the White-ringed but Social Flycatchers are very common and found everywhere, while the White-ringed is rarer and (as far as I know) are found in forests (unlikely to be found perched in a wire). Hope this helps!

And thank you for sharing your lovely Flycatcher!!! :t:

Nice one.
Another vote for Social Flycatcher.
As Marian says they are quite common -esp. in CR. We saw them in Tortuguero in July of this year (Laguna Lodge).