Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the burden and does disclose the key behavior: the tool writes without sending. However, it does not mention that it overwrites existing draft text by default unless append=true, though that is already captured in the append parameter schema. Adequate but not richly transparent.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.