docs: clarify settings guidance in AGENTS

Co-authored-by: openhands <openhands@all-hands.dev>

Author: openhands-agent

AGENTS.md

@@ -303,7 +303,7 @@ Note: This is separate from `persistence_dir` which is used for conversation sta
 - Build agent-server: `make build-server` (output: `dist/agent-server/`)
 - Clean caches: `make clean`
 - Run SDK examples: see [openhands-sdk/openhands/sdk/AGENTS.md](openhands-sdk/openhands/sdk/AGENTS.md).
-- Programmatic settings schemas should annotate the canonical SDK model fields (for example `LLM`) and export only those annotated fields, instead of introducing duplicate subset config models that can drift from the source of truth.
+- Programmatic settings live in `openhands-sdk/openhands/sdk/settings.py`. Treat `AgentSettings` and `AgentSettings.export_schema()` as the canonical SDK settings surface, and annotate existing SDK model fields (for example `LLM`) instead of maintaining a second, separately curated settings surface for the same values.
 
 </QUICK_COMMANDS>