fix(time): preserve McpError INVALID_PARAMS code in call_tool error handler

[basilalshukaili]

Summary

call_tool in src/time/src/mcp_server_time/server.py wraps its entire body in try … except Exception as e: raise ValueError(…). McpError (raised by get_zoneinfo for unknown timezone names) is a subclass of Exception, so it was silently caught and re-raised as a plain ValueError. This discarded the structured INVALID_PARAMS error code that the MCP transport layer uses to distinguish client errors from server faults — causing MCP clients that inspect error codes to see an opaque server error instead of a proper "invalid argument" response.

Fix

Add an explicit except McpError: raise guard before the broad handler so McpError propagates to the transport layer with its code intact:

except McpError:
    raise           # preserve INVALID_PARAMS / structured error code
except Exception as e:
    raise ValueError(f"Error processing mcp-server-time query: {str(e)}")

Also fixes a minor description typo: "Get current time in a specific timezones" → "Get current time in a specific timezone".

Tests

Added three assertions that verify McpError carries INVALID_PARAMS when an invalid timezone is supplied to get_current_time and both positions of convert_time. These tests fail on the previous code (a ValueError is raised instead of McpError).

uv run pytest src/time/test/time_server_test.py  # 41 passed