Tool for sending a message to a pre-bound target agent.

The target is configured by whoever registers this tool into a tool scope (sub-loop, subagent, or future phonebook skill). The LLM only supplies the content. There is no LLM-supplied to: parameter — that is by design, so the same tool module can serve every messaging context with no special-casing.

Context

Expects the following keys in %ToolExecution{}.context:

• :target — %SkillKit.AgentRef{} of the agent to message. The tool delegates to SkillKit.send_message/2, which casts a %UserMessage{} to that agent's mailbox.

Behavior

Returns {:ok, "Message sent."} on successful cast. Returns {:error, "Target agent is not running."} if the target's mailbox process cannot be located.