agent-harness-fault-injection

# Agent Harness Fault Injection ## Overview Use a deterministic, non-production fault schedule to test whether an agent workflow preserves state, budgets, safety boundaries, and evidence when a dependency fails. The output is a small fault matrix, an event timeline, and a verdict that distinguishes recovered, contained, unrecoverable, and inconclusive runs. ## When to Use This Skill - Use when a multi-step agent, state machine, loop, or multi-agent workflow has a new recovery path. - Use when sandbox execution, an MCP/tool call, a worker, a checkpoint store, or memory can time out or disappear. - Use before claiming retry, resume, deadline, isolation, or partial-failure behavior is production-ready. - Use when a regression needs reproducible failure evidence instead of a random chaos run. Do not use this skill against a production target, real user data, live credentials, or an unbounded external service. Convert those cases to a local simulator or an authorized staging harness first. ## Safety and Boundary Preconditions 1. Freeze the workflow revision, model/prompt configuration, tool schemas, seed, input fixture, timeout, retry budget, deadline, and expected terminal states. 2. Run in a disposable sandbox with synthetic inputs and stubbed tools. Keep network disabled unless the test explicitly needs a local test server. 3. Make every injected failure an in-memory or fixture-controlled event. Never delete real data, revoke real credentials, kill an unrelated ...