Without having a specific poem to break down, I can only answer in generalities. Poetry summaries can vary quite a bit, too, because the summary could choose to focus on only explaining what happened in the poem, for example. For a ballad, that kind of summary makes sense because a ballad will narrate a story of sorts using rhyme, rhythm, and meter. This kind of summary would also include information about who is speaking and possible information about characters in the poem. If the poem is something like a haiku, then summarizing what 'happens' in the poem isn't always appropriate. That's because some poems don't describe actions; they describe images and/or feelings. In that case, then your summary becomes a bit more of an analysis of the figurative language that is used, the symbols that are created created, and the intended meaning of the poem. Finally, the summary of a poem might also include information on the actual structure of the poem. It will explain how the stanzas are organized, and it will explain what the rhythm, meter, and rhyme scheme of the poem are.

It might be more helpful if you suggested the actual poem that was being sought out.  One thing I have always felt in terms of analyzing the summative action in a poem is to identify the literal action that is happening in the poem.  Being able to focus on this might be able to give some level of structure ot the explanation of the surface meaning of the poem.  For example, in Ozymandias, what is literally happening in the poem?  This might involve determining who is speaking, what progression is evident, and how it concludes.  In doing this, one might be able to establish a summary of a poem.  A part of this would have to be determining the symbolic meaning of the poem.  This resolves in the idea of determining what might the poet seek to gain from writing this poem, what message might want to be sent out, and how their own personal beliefs fit into this scheme.  Establishing these elements behind surface and symbolic meaning can help form effective summaries of poems.