Should the poet, as an omniscient narrator in a novel, explain the meanings behind the images he is presenting or otherwise, should he only describe what he sees and leave the reader to conclude and understand the meaning?
Neither of course. The poet is supposed to get beyond the limits of description and explanation. He or she is supposed to get down into all the emotions we can feel and they are supposed to share these emotions with us, using words, using all sorts of languages, including body language and music. You can even kiss or hug a poet and you will feel the emotions flowing from him or her to you. Your question is similar to people who want to know if dreams are descriptive or explanatory. Neither of course. They are purely existential and emotional experiences at the purely mental level of one's inner imagination.
As a poet, I can say that all the grace and beauty of poetry is that the poet waits for the diverse and beautiful concepts and perceptions of his readers.
And if they ask her/ him, she/he can also say her/his opinion.
This creates a suitable environment to stimulate the imagination and creativity of the readers and they also feel the beauty and tenderness of the poem.
Perhaps this is why poets use symbols. Because symbols have different aspects and everyone receives a meaning from it according to their power of understanding and thinking.
Le poète est à différencier du romancier, auteur de fictions, qui combine et structure des histoires, met en scène des personnages, leur imagine des destins singuliers. Il en va autrement pour la poésie qui est descriptive, en ce sens où le monde, la nature et les êtres qui la peuplent et les saisons, sont saisis et rendus à travers une subjectivité, celle du poète, de son regard qui entend en percer les secrets et les communiquer, de ce fait, elle est aussi explicative. Les éléments extérieurs et intérieurs sont en intéraction constante.
The poet's task is totally different than that of the narrator: the poet neither narrates nor explains. Such comparison is certainly invalid. The poet's 'World' is his\her, and it is the reader's responsibility to dig deep fathoms to find the "jewel."
Salih Mahdi Hameed Alshukri thanks dear professor for the answer.
Indeed, I think poetry can not be judged on such a basis that is more relevant to prose writing, yet the question came to me as I was reading about the new poetry of the modern era (especially the poetry of the Imagist movement) where the poet is supposed to be objective (be precise and do not describe), let the reader come up with their own conclusions or readings. The problem with this movement was in the extremities they went to, some of them ended up writing poetry that has no depth just to be as objective as possible.
Just to add a point to all the great comments already made, a poet may, nevertheless, deploy the devices of description and narration here and there for a desired/ironic effect.