If the model only outputs the tool call as text after receiving the vLLM, it is usually not that Hermes is not connected, but that the tool call parameters are missing when the vLLM service is started. Hermes uses Hermes/Qwen class models are commonly used hermes , Llama 3.x commonly used llama3_json , DeepSeek, Mistral, etc. must follow the parser supported by vLLM.tool_choice: autoby default, and the vLLM side also needs to be explicitly turned on.Check the launch command first
_CODE_BLOCK_0_______Different models need to select the corresponding parser.
depends on whether these items
One sentence: vLLM tool does not work, first add--enable-auto-tool-choice and correct--tool-call-parser.
How to determine whether it is a vLLM or a model problem
/v1/chat/completions, bring the simplest tool schema, and see if there are structured tool calls in the return. If the API layer has returned only ordinary text, the problem is most likely vLLM parser or model capabilities; if the API layer is normal but Hermes is abnormal, check Hermes 'custom endpoint, model name, context length, and log.Official open source address: https://github.com/NousResearch/hermes-agent; Official document entry: https://hermes-agent.nousresearch.com/_.