Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations exist, so the description carries full burden. It discloses side effects (closing old positions, opening new ones), a prerequisite (user must own the fund), cost implication (friction), weight default behavior, and the return shape (updated roster entry and friction estimate). This is robust for a mutating tool.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.