Hi, I'm trying to compare variants identified in GATK and samtools with respect to variant attributes. I'm wondering how to add StrandOddsRatio annotations to a samtools generated VCF file. When I use the GATK VariantAnnotator tool, I get the warnings:

WARN 06:58:10,259 StrandBiasTest - No StrandBiasBySample annotation or read data was found. Strand bias annotations will not be output.

WARN 06:58:10,259 StrandBiasTest - No StrandBiasBySample annotation or read data was found. Strand bias annotations will not be output.

The VCF file I'm using has a FORMAT field:
##FORMAT=<ID=SP,Number=1,Type=Integer,Description="Phred-scaled strand bias P-value">
Are there specific FORMAT or INFO fields I need to produce so that the StrandBiasTest will run on GATK?

Thank you!