Consider deprecating old api API

**Problem**
When working with hooks, the error messages could be more descriptive.

**Suggestion**
Improve error handling and add detailed error messages.

**Context**
This would help with debugging and maintenance.

The issue names no files, tests, or entry points. Start by locating the hook error-handling path and references to the old API, then clarify which API is in scope and what messages are required. Done needs an agreed deprecation scope and concrete error-message expectations, followed by the relevant project checks.

索引モデルが issue の本文から書いたものです。