Improve types performance

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

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

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

No files, tests, or entry points are identified. Start by locating the handler error paths, then determine which failures need more descriptive messages; done means the relevant errors provide useful debugging context and the behavior is covered by appropriate tests.

Written by the indexing model from the issue text.