https://blog.cs2680.com/tags/tool-use/Recent content in Tool-Use on CS2680 Student BlogHugoen&copy; 2026 The President and Fellows of Harvard CollegeTue, 06 Oct 2026 00:00:00 +0000https://blog.cs2680.com/2026/assignment1/why-bash/Tue, 06 Oct 2026 00:00:00 +0000https://blog.cs2680.com/2026/assignment1/why-bash/<p>If you built a trajectory viewer for Assignment 1, you probably watched a lot of Bash go by. Many students built careful renderers for Read, Edit and Write, expecting those tools to fill their interfaces. Most of the file work arrived as <code>cat</code>, <code>sed -n</code>, heredocs and small Python patch scripts, all wrapped in Bash cards. In one case described in our <a href="https://blog.cs2680.com/2026/assignment1/agentic-coding-lessons/">lessons from the assignment</a>, an agent completed an entire bug fix through the shell without ever lighting up the student&rsquo;s edit view.</p> <p>We initially suspected the model or the way students prompted it. The submitted session logs pointed mostly to Claude Code itself: it told the agent to use the shell and removed the Bash tool&rsquo;s usual warning against file operations. Most installations also lacked dedicated search tools.</p>