The phrase "a note described" is correct and usable in written English.
It can be used when referring to a specific note that has been characterized or detailed in some way.
Example: "In the report, a note described the importance of following safety protocols during the experiment."
Alternatives: "a note mentioned" or "a note outlined".
At the bottom of the Ferriss press release, there's a note describing the company.
In 1903, Smith dissected him, sending the skeleton to Cunningham, with a note describing Wanamachoo as "the very lowest black-fellow [he'd] ever seen".
A note describing the treatment was also included with the book, so a reader could understand how the pages had initially been glued together.
This time, instead of American money, there were a few Turkish coins and a note describing some charms from that country.
In his Los Angeles gallery, a note describing his absence was the only thing viewers found when they arrived for his scheduled exhibition.
On the flip side, not long before the playground incident, an Issaquah high school student was accused of writing a note describing how he would stab a teacher to death.
The next day, after Perelman failed to appear, we left a box of pearl tea and a note describing some of the questions we hoped to discuss with him.
Waiting to die in the sunken submarine Kursk last August, a young Russian sailor scrawled a note describing how he and 22 others had rushed to a rear escape hatch only to find there was no way out.
But a senior official with the Palestinian Preventive Security, another organization, said the young woman had left behind a note describing her troubles with her family and had then run off.
The Chinese "nurses" are easy to spot: they stroll in, hand over a note describing the model they want and leave as soon as they get it, whereas an ordinary buyer will often take their gadget out for a test drive before leaving the store and ask sales staff numerous questions.
