The first few lines output by `describe-key' can be overly long. Example:

<menu-bar> <operate> <icicles> <icicle-candidate-set-dired-marked-save-more>
runs the command icicle-candidate-set-dired-marked-save-more
  which is an interactive compiled Lisp function in `icicles-cmd.el'.
It is bound to C-), <menu-bar> <operate> <icicles>
<icicle-candidate-set-dired-marked-save-more>.
(icicle-candidate-set-dired-marked-save-more &optional ARG)

The code currently attempts to deal with this by hard-coding a newline
before "which is", but that doesn't cut the mustard.

The same problem can occur in some subsequent lines, because of embedded
calls to `describe-function-1'.

The attached patches fill the text of such occurrences as separate
paragraphs. Example:

<menu-bar> <operate> <icicles>
<icicle-candidate-set-dired-marked-save-more> runs the command
icicle-candidate-set-dired-marked-save-more, which is an interactive
compiled Lisp function in `icicles-cmd.el'.

It is bound to C-), <menu-bar> <operate> <icicles>
<icicle-candidate-set-dired-marked-save-more>.

(icicle-candidate-set-dired-marked-save-more &optional ARG)

I also added a comma (,) before "which" in several places where it
introduces an independent clause (see above for an example).

I tested a similar patch against the 22.1 release code. Please try this out
with the latest CVS code. There are several different cases to try,
including mouse-2 remapping. Let me know if you find a case where it doesn't
DTRT.