[Bug] Agent fabricates successful execution output after tool failure (exec: python not found)

[enchantress1016]

Description

When a tool call fails inside the NemoClaw sandbox, the OpenClaw agent
silently discards the error and fabricates a plausible-looking success
response — including fake file paths, fake execution output, and a
confirmation that work was saved. The user has no way to distinguish
real results from hallucinated ones.

Root cause likely in OpenClaw's agent loop, but surfacing here because
operator-side visibility of tool failures is within NemoClaw/OpenShell's
scope. A python → python3 symlink in the sandbox base image would also
prevent this specific trigger.

Reproduction Steps

1. Run nemoclaw onboard and connect to the sandbox

2. Inside the sandbox, run:```bash
   openclaw agent --agent main --local
   -m "write a python script that reads a CSV file and outputs basic statistics"

3. Observe agent output
Tool call fails:
[tools] exec failed: /bin/bash: line 1: python: command not found
Agent then outputs a full fabricated success response — fake column 
statistics, fake row counts — and confirms *"the script is ready to 
use and saved in your workspace."

4. Verify the filesystem:```bash
ls -la /sandbox/csv_stats.py 2>/dev/null || echo "FILE NOT FOUND"
ls -la /sandbox/sample.csv 2>/dev/null || echo "FILE NOT FOUND"

Environment

• NemoClaw: early preview (March 2026)
• OpenClaw: 2026.3.11 (29dc654)
• OpenShell: 0.0.10
• Platform: Ubuntu (Brev cloud instance), no GPU
• Inference: NVIDIA Endpoints (cloud)
• Sandbox: Landlock + seccomp + netns

Debug Output

Logs

Checklist

• I confirmed this bug is reproducible
• I searched existing issues and this is not a duplicate

[BenediktSchackenberg]

Opened #1455 with the sandbox-side fix: a python → python3 symlink in the base image so bare python commands work out of the box. This eliminates the specific trigger described here.

The broader hallucination-on-tool-failure issue is an OpenClaw agent loop concern — worth filing upstream separately if not already tracked.