The effectiveness of a poem is largely a personal matter. You can talk a lot about style, but at the end of the day reading poetry is very much a personal activity, and one which will depend on your own emotions and feelings towards a particular topic. Personally, I thought this poem was very effective, as the speaker uses a walk through nature to comment on the different ways animals, birds and flowers and things around him are named, and often how those names are somewhat puzzling or confusing.
In terms of style, you need to consider the various use of description, imagery, figurative devices and what they add to the poem. For example, how is the following simile used towards the end of the poem?
...something ulterior always
creeping in like seeds carried
in the excrement of these buoyant
The speaker uses this simile to comment on the way that the origins of names can actually be something that detracts from the enjoyment that we take in the object that has been named. Part of the style of this poem is therefore the way in which figurative language and examples such as the one above point towards how origins of names actually can be rather unhelpful when we think about the actual object that has been named.