Purpose: There are well-established guidelines for the recording, transcription, and analysis of spontaneous oral language samples by researchers, educators, and speech pathologists. In contrast, there is presently no consensus regarding methods for the written documentation of sign language samples. The Handshape Analysis Recording Tool (HART) is an innovative method for documenting and analyzing word level samples of signed languages in real time. Fluent sign language users can document the expressive sign productions of children to gather data on sign use and accuracy. Method: The HART was developed to document children's productions in Australian Sign Language (Auslan) in a bilingual-bicultural educational program for the Deaf in Australia. This written method was piloted with a group of fluent signing Deaf educational staff in 2014-2016, then used in 2022-2023 with a group of fluent signing professionals to examine inter- and intrarater reliability when coding parameters of sign accuracy. Results: Interrater reliability measured by Gwet's Agreement Coefficient, was "good" to "very good" across the four phonological parameters that are components of every sign: location, movement, handshape, and orientation. Conclusions: The findings of this study indicate that the HART can be a reliable tool for coding the accuracy of location, orientation, movement, and handshape parameters of Auslan phonology when used by professionals fluent in Auslan. The HART can be utilized with any sign language to gather word level sign language samples in a written form and document the phonological accuracy of signed productions.