Behavioral guard plugins watch the agent loop for unproductive patterns and enforce per-call budgets. A guard is a self-contained consumer of core seams, not a swappable capability.

Package	Role	ctx key
`repeat-tool-guard/`	Advisory reminders for repeated tool calls	listens on tool and agent events
`timeout-policy/`	Arms per-call tool deadlines as deployment policy	registers a `tools/execute` listener

Reminders travel as additionalContexts on the tools/post-execute decision and are appended as logged plugin-sourced user/message events (tools); the timeout split across dsh-timeout, capability termination, and this policy layer is recorded in the timeout-library Agent Note.