Ollama models that don't support tools receive tool definitions, causing 400 errors #2787

Summary

The inference layer sends tool definitions to ollama models that don't support them (e.g. gemma3:1b-it-qat), causing 400 Bad Request errors: "does not support tools".

Problem

What happened: When a chat request includes tool definitions and routes through an ollama model that doesn't support tools, the request fails with:

{"error":{"message":"registry.ollama.ai/library/gemma3:1b-it-qat does not support tools","type":"invalid_request_error","param":null,"code":null}}

Expected: The inference layer should either:

1. Strip tool definitions from the request when the model doesn't support tools, OR
2. Detect the "does not support tools" error and retry without tools, OR
3. Pre-check model capabilities before sending tools

Impact: 14 events in Sentry (TAURI-RUST-4K7), escalating. Affects any ollama model without tool support. The trace also shows related errors with bge-m3:latest ("does not support chat") — embedding models being used for chat.

Steps to reproduce:

1. Configure ollama with a model that doesn't support tools (e.g. gemma3:1b-it-qat)
2. Send a chat message that includes tool definitions
3. Observe 400 error

Version / Platform: openhuman@0.56.0, Windows 10.0.26200, rustc 1.93.0

Solution (optional)

The ollama provider should handle the "does not support tools" error gracefully. Options:

1. Best: Query ollama's /api/show endpoint at provider init to check model capabilities, and strip tools for non-supporting models
2. Simpler: Catch the specific "does not support tools" 400 error and retry the request without tools
3. Minimum: Strip tools from the request body when the model name is known to not support tools (less robust)

Acceptance criteria

• Repro gone — Ollama models without tool support no longer get 400 errors from tool definitions being sent.
• Regression safety — Unit test added to verify tool stripping for non-tool-supporting models.
• Diff coverage >= 80% — the fix PR meets the changed-lines coverage gate.
• Tool-supporting models unaffected — models that DO support tools still receive them.

Related

• Sentry: https://sentry.tinyhumans.ai/organizations/tinyhumans/issues/5232/
• Same trace shows bge-m3:latest "does not support chat" errors (embedding model misuse)