Source Intelligence

DisclaimerUnofficial, and not affiliated with Anthropic. Nearly all of this is read straight out of what ships: npm bundles, captured prompts, published docs. Anthropic's own notes go in verbatim, marked as theirs. The rest is my reading, and every entry carries the strings behind it. If one looks wrong, vote it down and say why.

All of v2.1.53 Home All releases olderv2.1.52 v2.1.54newer
Claude Code v2.1.53

Restructured Bash Tool Description

The Bash tool system prompt has been completely rewritten from a monolithic template literal into a modular, array-based builder. While the overall guidance is similar, it now includes:

  • A dedicated "# Instructions" section with clearer organization
  • Explicit "For git commands:" subsection with safer defaults guidance
  • A new "Avoid unnecessary sleep commands:" subsection with six specific anti-sleep rules, including: don't poll background tasks, use run_in_background for long-running commands, don't retry in sleep loops, and keep sleep durations to 1-5 seconds
  • Sandbox description restructured into a more readable format
Evidence

New modular Bash description builder function (search for "Avoid unnecessary" and "Do not sleep between commands")

Strings lifted out of the shipped bundle, so the claim above can be checked against them.

See this entry in the whole of v2.1.53 →