xr.doctor(): diagnostics on a Dataset / DataArray ?

Is your feature request related to a problem?

Recently I've been reading through various issue reports here and there (GH issues and discussions, forums, etc.) and I'm wondering if it wouldn't be useful to have some function in Xarray that inspects a Dataset or DataArray and reports a bunch of diagnostics, so that the community could better help troubleshooting performance or other issues faced by users.

It's not always obvious where to look (e.g., number of chunks of a dask array, number of tasks of a dask graph, etc.) to diagnose issues, sometimes even for experienced users.

Describe the solution you'd like

A xr.doctor(dataset_or_dataarray) top-level function (or Dataset.doctor() / DataArray.doctor() methods) that would perform a battery of checks and return helpful diagnostics, e.g.,

• "Data variable "x" wraps a dask array that contains a lot of tasks, which may affect performance"
• "Data variable "x" wraps a dask array that contains many small chunks"
• ... possibly many other diagnostics?

Describe alternatives you've considered

None

Additional context

No response

Start by reviewing the proposed xr.doctor(dataset_or_dataarray) entry point and the example diagnostics for Dask task counts and chunk sizes. Done would require a defined, agreed battery of diagnostics and a clear return format, but the issue does not identify files, tests, or a settled scope.