[BUG] Bash tool incorrectly reports "Error" for normal non-zero exit codes

Environment

• Platform (select one): Anthropic API
• Claude CLI version: 1.0.83 (Claude Code)
• Operating System: macOS (Darwin 22.6.0)
• Terminal: Terminal App

Bug Description

The Bash tool incorrectly reports <error>Error</error> for any command that exits with a non-zero status code, even when the non-zero exit represents normal program behavior rather than an actual error.

Steps to Reproduce

1. Prompt Claude Code to run any command via the Bash tool that normally exits with code 1 for "no results" or similar normal conditions
2. Examples:

• grep "nonexistent_term" some_file.txt
• false

1. Observe the tool result shows <error>Error</error>
2. Compare with commands that exit 0: true shows <system>Tool ran without output or errors</system>
3. Examples:

• grep "existent_term" some_file.txt
• true

Expected Behavior

The Bash tool should distinguish between:

• Actual errors: Command not found, permission denied, syntax errors, etc. → Show as error
• Normal non-zero exits: No matches found, logical false conditions, files differ, etc. → Show as normal completion with no output

Many Unix tools use exit codes semantically where non-zero doesn't indicate failure.

Actual Behavior

The Bash tool shows <error>Error</error> for any non-zero exit code, making it impossible to distinguish between actual command failures and normal program behavior.