hermes - 💡(How to fix) Fix [RFC] Attempt JSON repair on truncated tool call args before aborting

Problem

When the model emits truncated tool call arguments (finish_reason mismatched by router or provider, leaving a trailing {"key": or [{"name": "foo" without closing braces/brackets), conversation_loop.py currently returns an abort immediately. This costs a full API round-trip — the model has to re-generate its entire response.

Proposed solution

Before aborting, pass truncated arguments through _repair_tool_call_arguments — the same repair function already used for API sanitization (trailing commas, unclosed braces/brackets, control characters, etc.).

If repair succeeds on ALL truncated calls (valid JSON after fix), clear the invalid-args list and continue normally. Only abort if repair genuinely fails.

In practice, most truncations are simply an unclosed trailing object/array — repair handles them trivially. I've observed this saving 20-30 retry cycles per day in heavy usage.

The change is ~40 lines in the truncation detection block of conversation_loop.py — no new dependencies, no new abstractions. I'll open a PR if this looks good.

Prior art

Adapted from a similar approach in Reasonix's trunkation handling — attempting JSON repair before falling back to abort has proven effective there.