Tsuneie is transmitted as a swordsmith of the Hatakeda branch within the Osafune school of Bizen Province. Although the Meikan and related signature references place the first generation in the mid-Kamakura period around the Shoo era (1288-1293), and examples bearing Oan-era dates of the Nanbokucho period are also recorded, extant works that predate the Oei era are exceedingly rare. Tsuneie stands alongside Iesuke as one of the capable smiths of Oei-Bizen, coming after the foundational masters Morimitsu and Yasumitsu, and his workmanship closely resembles that of Yasumitsu from the same period. Despite being recorded as "Osafune" and transmitted as Hatakeda lineage, the NBTHK observes that there are no grounds — whether in workmanship, the character of the signature, or any other point — by which one could distinguish his production from Osafune work.
Tsuneie's forging characteristically shows ko-itame-hada closely worked, with ji-nie adhering and bo-utsuri clearly standing — hallmarks that plainly display the style of Oei-Bizen. His tempering frequently features gunome with opened bases into which choji is mixed, often with small ashi and yo, and a nioiguchi that tends toward tightness and is saeru — bright and clear. However, the NBTHK further notes that Tsuneie was also adept at producing quiet suguha tempers, demonstrating a versatility beyond his more florid work. Both tachi and wakizashi often show a build that is long in proportion to a standard mihaba, with notably thick kasane, lending a dignified and imposing presence.
The finest designated examples by Tsuneie are praised as especially well-executed works, excellent in both jigane and hamon, with a splendidly florid temper of gunome and choji. The NBTHK consistently commends those pieces in which both ji and ha are kenzen — sound and well-preserved — and in which the workmanship is well ordered. The well-refined jigane is described as bright and clear, and the dignified shape with its thick kasane is deemed particularly appealing. Tsuneie's position as a representative smith of Oei-era Bizen is firmly established, sharing common traits with his contemporaries while maintaining a workmanship of consistent refinement.