--json, CLI errors are written to standard error as human-readable text beginning with error:. With --json, errors contain schema_version and an error object with code, message, and exit_code.
Invalid arguments use the
invalid_arguments error code with Clap’s nonzero exit code.
MCP reports missing meetings as invalid parameters. Database and serialization failures are internal MCP errors.
Do not recover by creating tables, running migrations, or issuing SQL. The desktop app owns schema initialization and migrations.