Feature request: alt_text on tf.summary name

Most people rely on the log_dir name to identify an experiment, but this can get out of hand pretty quickly.

It would be amazing if there was an easily reachable section in TensorBoard where I could see more details for a particular run (some people use "Text" summaries, but these are not easily visible from any tab).

A simple way would be to use an alt_text (the text box that appears when the mouse is stationary over an item).

This is how the TensorBoard API could be adapted to support this:

logdir='n_samples_1/20170530_141605'
description='more details on experiment can be provided here, and visualized like this via an html "alt_text"'
writer = tf.contrib.summary.create_file_writer(log_dir, description=description)

This is what it would look like:

Start by tracing the TensorBoard API behind tf.contrib.summary.create_file_writer and the UI that displays details for a run. Determine how a description could flow from the writer to an easily reachable run view and appear as hover text; done means the description is accepted, stored, and visible for the selected experiment.