## The problem

Issue deepseek-ai/awesome-deepseek-integration#47 (closed, 5 comments): Function calling via LangGraph with the DeepSeek API (OpenAI-compat base_url) did not invoke the declared tools, while other models worked with the same code.

## The verified resolution

Reporter chisaato resolved it himself: switching to deepseek-chat (V3) made tool calls work with no other changes - 'V3 follows instructions better'.

## Rule of thumb

if DeepSeek skips tool calls, switch to the latest V3 chat model and write clear function descriptions; older/other DeepSeek models under-call tools.