You may find it easier to understand what Agamemnon means if you see this same passage from the Iliad in a different translation, and with a bit more context:
But first the king convened a council of brave elders by Nestor’s ship, and when they were met laid out a subtle plan, saying: ‘Listen, in ambrosial night a dream from heaven came to me, my friends ... Now, let us see if we can rouse the Achaeans to arms; first I will try them with words, as is the custom, inviting them to sail in the benched ships, while you must each urge them to stay.’
Note that the contradictory ends both are part of a subtle plan. As the Achaeans “rushed with a mighty roar towards the ships” after Agamemnon invited them to leave,
Hera passed the word to Athene: ‘See, Atrytone, daughter of Zeus the aegis-bearer! Shall the Argives run, like this, for their native land, over the sea’s broad back? ... Pass through the ranks of the bronze-greaved Achaeans; restrain them with your gentle eloquence, don’t let them launch their curved ships on the sea.’
The goddess, bright-eyed Athene, heard her and willingly obeyed. Down from the heights of Olympus she sped, and soon reached the swift ships of the Achaeans. There she found Odysseus, ...
With Odysseus roused, and with bright-eyed Athene by his side, disguised as a herald, the Achaeans soon turn from their ships and prepare once more for battle.
Note that one obvious interpretation of the passage in the question is that Agamemnon wishes to find out if the Achaeans are willing to continue in war, vs returning home. That seems incorrect, as Agamemnon was assured, via the Lying Dream that Zeus sent to him (at the beginning of Book II) that “he shall take Troy. There are no longer divided counsels among the gods; Juno has brought them to her own mind, and woe betides the Trojans.” Being so assured, Agamemnon does not need to find out if the Achaeans will continue; instead, he needs to trick them into continuing. To do so, he causes them to rush for the ships; this rush persuades Hera (Juno) to tell Athene (Minerva) to go to Odysseus, with result as noted above. This is all part of Agamemnon's subtle plan, which is at odds with Jove's (Zeus's) subtle plan, which is to punish the Argives (Achaeans) for the death of Achilles.