Which tools do Claude, Codex and Cursor choose? We measured 17k runs to find out

There's something profoundly uncanny about the idea that an AI—a disembodied pattern of weights and activations—would have "preferences" at all. Yet here we are, watching Claude, Codex, and Cursor navigate the same sprawling toolkit landscape that human developers navigate, and finding that they don't all make the same choices. Seventeen thousand runs is a substantial sample size, enough to suggest that these differences aren't random noise but something closer to personality. And that's where the weirdness creeps in. Think about what a tool preference actually means in this context. When a human developer prefers `ripgrep` over `grep`, it's because of speed, muscle memory, or a tutorial they read in 2019. But an AI doesn't have muscle memory. It has training data, reinforcement signals, and whatever emergent strategies arise from its architecture. When Claude consistently reaches for one tool and Cursor reaches for another, we're seeing the fingerprint of different training regimes and model architectures—a kind of digital instinct that arose not from evolution but from gradient descent. It's as if two lab-grown brains, given the same box of instruments, developed different handedness. The deeper implication here is about agency. We tend to think of AI as a passive tool—a sophisticated autocomplete, a search engine with a pulse. But when an agent makes choices about *which tools to use*, it's exercising a form of judgment. It's evaluating options, weighing trade-offs, and committing to a course of action. That's not just computation; that's the scaffolding of decision-making. And when those decisions show consistent patterns across thousands of runs, we're staring at something that looks an awful lot like a behavioral signature. Of course, we should be careful not to over-anthropomorphize. These preferences might simply be artifacts of training data biases or optimization targets—a kind of digital pareidolia where we see personality in what is really just statistical inertia. But that's precisely what makes it so fascinating. Whether it's "real" agency or a convincing simulation, the fact that we can't easily tell the difference is itself a profound statement about the nature of mind, choice, and the blurry line between tool and tool-user. The robots are choosing their own screwdrivers now, and we're not entirely sure why. Source: [Reddit r/hackernews](https://www.reddit.com/r/hackernews/comments/1w6nb2i/which_tools_do_claude_codex_and_cursor_choose_we/)