Stop Letting Your Agent Say 'Done': Mac MCP Author on Tool Success vs Task Success
bulutarkan · reddit · 2026-10-20
The maintainer of open-source Mac MCP shares a subtle failure mode from using ChatGPT as an orchestrator over his Mac: a tool executes an action, the assistant confidently reports 'done', but the outside system never accepted the result.
Examples:
- A reply is visibly in a text field, but the site never accepted a real input event or submission
- A calendar API returns a recurring event that looks right but isn't the requested date
- A mail/phone action opened an interface without proving the message was sent
His fix: change the contract so the agent separates 'I attempted this' from 'I checked that it happened' — verify via read-back where possible, and report uncertainty honestly instead of manufacturing certainty. Open source at github.com/bulutarkan/mac-mcp.
More from coding & agent
- Decisions API integration with Live API showcased as fast GPT backend in demo — gabrielchua · 2026-10-20
- DoorDash runs 130K automated tasks a month: inside 8 AI software factories — Pavan_Belagatti · 2026-10-20
- DeepSeek-V4.1-Flash-1017 Hits Qoder Day One, Free at 0.0x Credits Until Oct 24 — alifcoder · 2026-10-20
- Agents Ask for Approval 20 Times a Day—Are You Still Reviewing or Just Clicking Yes? — Glittering812 · 2026-10-20
- Skyrim AI mod lets bards compose songs about your adventures — and got flamed off Reddit — ReignMocap · 2026-10-20
- LangChain's Harrison Chase: how vertical agents differentiate via context, harness and model — hwchase17 · 2026-10-20