We study decentralized task coordination. Tasks are of varying complexity and agents asymmetric: agents capable of completing high-level tasks may also take on tasks originally contracted by lower-level agents, facilitating system-wide cost reductions. We suggest a family of decentralized two-stage mechanisms, in which agents first announce preferred individual workloads and then bargain over the induced joint cost savings. The second-stage negotiations depend on the first-stage announcements as specified through the mechanism's recognition function. We characterize mechanisms that incentivize cost-effective task allocation and further single out a particular mechanism, which additionally ensures a fair distribution of the system-wide cost savings.