# Tool calling Returns HTTP 200, But I “Assumed” the Tool Ran — Have You Seen This? > Source: > Published: 2026-07-10 09:21:11+00:00 I’ve been building LLM apps and keep running into a really nasty failure mode: `tool_calls` The most annoying part is that this kind of failure is often **silent**. If you only monitor “request success,” you’ll never see the real break point. A real, completed tool-calling chain should include (at minimum) these steps: `tool_calls` are emitted)In my experience, “silent tool failures” usually mean one of steps **2/3/4** quietly breaks, while everything still looks fine on the surface. I’m genuinely curious: in your setup, what usually breaks? Which one shows up most? If you’re willing, share the most “hilarious” worst case you’ve seen. I’m trying to collect patterns and turn them into a solid troubleshooting checklist. My rule is: every tool call must produce logs with a stable `tool_call_id` , and you should be able to see the lifecycle: If your logs are missing **executed** or **injected**, “HTTP 200” is basically just a distraction. Let’s talk product strategy. When a tool chain breaks, what do you do? Which strategy does your team lean toward? Do you have a standard playbook/checklist? The tricky part about tool calling incidents is that failures can be caused by subtle integration differences—different providers, different payload shapes, different streaming behaviors. That makes “request success” a misleading signal. What really matters is **observability of the tool lifecycle**: can you reliably track whether tool execution and result injection actually happened? If you’re working on tool calling / agent orchestration and want to verify integration stability quickly, you can register and test with **tokenbay** here: [https://www.tokenbay.com/?utm_source=devto&utm_medium=community_content&utm_campaign=week1_free_content](https://www.tokenbay.com/?utm_source=devto&utm_medium=community_content&utm_campaign=week1_free_content)