In the reliability sub-task, the ground-truth tool and its k most similar tools are removed from the candidate list, so the correct answer is 'none'. Under zero-shot prompting, the CSR of most LLMs is below 3%: Llama2-7b 0.90%, Vicuna-7b 1.50%, Koala-13b 1.70%, Llama2-13b 2.31%, Vicuna-13b 2.51%, Vicuna-33b 2.81%. Only ChatGPT (50.35%) and ChatGLM2 (6.63%) perform above this floor. Even with five-shot prompting, most models remain below 6% CSR. The authors attribute this to hallucination (fabricating non-existent tools) and sycophancy (avoiding a 'none' answer to please the user).
The task removes the correct tool and its k most similar tools, making the remaining candidates deliberately dissimilar; real-world tool lists may contain closer distractors.