Streaming protocol compatibility in action: analyzing how null causes agent tool call failures

On November 2, 2026, an article titled "How a Single null Can Break Agent Tool Calling: Streaming Protocol Compatibility in Practice" was published on Juejin, a Chinese developer platform. The piece examines a failure mode that appears during streaming tool calls: when a null value occurs in a subsequent response fragment, the agent's tool call can break. Drawing on a public fix, the article explains why the failure happens and walks through concrete remedies, including processing incremental fields according to the response index, preserving rejection branches, and validating boundaries. It also addresses the question of when an existing identity should be retained when a later fragment in a streaming tool call comes back as null. As of November 2, 2026, only this single report is available, and there is no further coverage describing subsequent developments or fallout.