Others w more technical knowledge than me will have more/better answers, but I think that one way to "know" (besides listening) is to look at the impedance characteristics of the speaker. Higher overall impedance and a relatively constant impedance over the audible bandwidth is a good clue that the speaker will match well w tubes. OTOH, a significant reduction in impedance, esp. in the bass, indicates that the speaker will require more wattage at those frequencies, which a tube amp is not designed to/is not able to deliver, resulting in a bass-weak presentation. An amp that "doubles down" ( delivers twice the output wattage) with a halving of the load impedance) will be better able to drive that speaker in the lower frequencies and will have a more robust bass presentation.
Considering the issue further, constant voltage sources (SS amps) deliver less power into a higher impedance load, so speakers with a high impedance SHOULD mate better with tube amps. Conversely, a tube amp will not be able to deliver steady wattage to a speaker with wide swings in impedance; hence the generalization that speakers w a flat impedance curve mate well w tube amps.
Considering the issue further, constant voltage sources (SS amps) deliver less power into a higher impedance load, so speakers with a high impedance SHOULD mate better with tube amps. Conversely, a tube amp will not be able to deliver steady wattage to a speaker with wide swings in impedance; hence the generalization that speakers w a flat impedance curve mate well w tube amps.