I'd like to avoid test a lot. One reason Robert and JS_Harris mentioned: Google sometimes breaks the basic rules on purpose, so you can't be sure for your testing results. Another reason is having time....
It's not necessary for me to have a very big description. I just like to have a good short description which is shown as often as possible and not shortened by dots. The dots don't look very teasing to users... so "incomplete" and "lacking"... bad subconscious psycological effect...
The title tag obviously is only determined by pixels and you can check this by Google itsself! Use the testing tool for structured data by inserting the whole title tag as code in the html tab. Unfortunately this doesn't work with the description, at least not for me, but check it.
Nice idea, but making curious is already the task of the whole decription AND furthermore promising to fulfill awakened needs/interests. I'd like to accomplish this both completely.
Nice idea, having a plan A and B at the same time. If Google shows the first 150 characters you don#t have shortening dots?