Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description bears the responsibility for behavioral disclosure. It adds 'safe, minimal' and 'syntax' as qualifiers, which communicates conservative behavior and scope, but it does not state whether the code is modified in place or returned, how errors are handled, or what kinds of fixes are applied.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.