Improve error messages in services

**Problem**
When working with api, 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 service and API error-handling paths in the Shell code, then document the current failure cases and define the expected descriptive messages. Done means relevant errors provide useful debugging context and the affected behavior is covered by tests.

Written by the indexing model from the issue text.