Tool messages

Tool messages let you define static messages that are surfaced to the user as a tool progresses through its lifecycle:

1. Start — Message delivered when the tool is initiated
2. Complete — Message delivered when the tool finishes successfully
3. Failed — Message delivered if the tool encounters an error
4. Delayed — Message delivered if the tool takes longer than a specified duration (default: 3000ms, configurable)

This provides clear, predictable feedback during tool execution, improving transparency and user trust—especially for long-running or failure-prone tools.