This paper reports on the results of a pilot study that was run to assess the labeling consistency of the proposed approach in Sp-ToBI before starting a large-scale production of annotations in the project Glissando. This test should serve to refine the model and to maintain consistently the annotation conventions across transcription sites. The Spanish ToBI labeling system has been proved as an effective system to annotate intonation for Spanish, although the annotation conventions across transcribers require a broader consensus. This is specially needed in the following pitch accents: high pitch accent (H*) vs rising pitch accent (L+H*), downstepped pitch accents versus non-downstepped counterparts, and mid tones. A related issue is the difficulty to decide in a very low pitch range if a tone is present or if the syllable has been unaccented. Moreover, the statistical procedures will shed light on the most confusable tones suggesting new approaches for the automatic prediction of ToBI labels in a Spanish Spoken corpus.