Ollama's Silent Tool-Call Failures: Conversation-History Round-Trip, Dropped Calls and Retyped Arguments
An agent loop calls a local Ollama server, the HTTP status is 200, the stream ends cleanly, and the assistant message contains nothing: no content, no tool_calls, done_reason: "stop". The loop treats that as “the model is done” and stops. Nothing was done. No error was raised. That is the failure this article is about. It is not one bug with one cause. Four separate, currently open reports against Ollama between versions 0.34.1 and 0.40.8 describe four different ways a tool call disappears or comes back mutated, and the source of tag v0.40.12 shows which of those paths are still present in the newest release at the time of writing. ...