What is Achilles’ first reaction to the appearance of his friends? What does this say about Agamemnon’s choice of messengers?

He basically accuses them of lying to him,

"I hate like the gates of Hell any man
who says one thing while thinking something else
which stays hidden in his mind."

He does give praise to his messangers although he might have been a little ironic,

"Odysseus of the nimble wits, royal son of Laertes,"