It’s really interesting that you both have the same discrepancy between T/F and agreeableness, and the magnitude of that difference is also interesting. I wonder whether that particular discrepancy is more common than others; if the correlation between T/F and agreeableness is weaker, it would presumably be more common than on other dimensions, but does it tend to go in the direction it does for both of you, I.E. more "agreeable" than "feeling"?
It’s true that, although they seem to be tapping into roughly the same thing, there are significant differences between the two, like the "logical" aspects of a T preference not being reflected in low agreeableness descriptions. The "straightforwardness" facet of agreeableness doesn’t strike me as inconsistent with a T preference; it might even be more T than F, if anything. In that respect, it’s quite similar to the issue of J types supposedly being more decisive, but the Big Five having "deliberation" as one of the conscientiousness facets. In both cases, the theories assign the same or similar traits to the opposite ends of the dimension. "Straightforward individuals are frank, sincere, and ingenuous. Low scorers are more willing to manipulate others through flattery, craftiness, or deception." Compare that to the descriptions of T types as the more invariably honest ones, with F types being more willing to bend the truth for the sake of being kind. I’d also suggest that doing things to make others feel better isn’t all that different from manipulation; perhaps it could be described, at least some of the time, as a "good kind of manipulation". The tendency/ability to alter people’s feelings for the sake of a desired outcome, perhaps at the expense of complete honesty, can be either a positive or a negative. I don’t mean to suggest that there’s necessarily anything sinister about wanting to make people feel good, or that a typical F is "manipulative" in the usual, value-laden sense of the term. I’m just pointing out that, if we stop making value judgements, "healthy" traits are often surprisingly similar to "unhealthy" ones, the only differences being in things like their consequences or social acceptability within a particular context rather than personality differences like thought processes or behaviour.
