Open WebUI tool calls fail locally

This looks like a tool-calling stack problem, not a one-off bad prompt. Open WebUI’s docs make the tradeoff clear: Native Mode is the supported path for reliable tool use, and weaker local models are exactly where structured tool calls start to fall apart.

• –Open WebUI says legacy prompt-based fallback is unsupported; Native Mode is the intended path for modern tools.
• –LM Studio can expose OpenAI-style tools, but the model still has to emit well-formed tool calls for parsing to work.
• –Smaller local models may handle simple, single-step tools but struggle with multi-step selection, JSON formatting, and stateful tool chaining.
• –If weather and Reddit tools fail consistently, check model capabilities, per-chat tool toggles, and whether the tool schema is too complex for the model.
• –The practical fix is usually less “more prompting” and more “better tool-use model, cleaner schema, Native Mode everywhere.”