Agent Harness Design
Eleven operational reference sheets for designing a safe, observable agent harness. They are situational — load only the one(s) relevant to the current task from references/ (this is why they live in a skill rather than always-on rules: building an agent harness is occasional, so the detail should not bloat every session's context).
references/agent-tool-design.md— 15-class risk taxonomy, 7-type permission decision object, draft/commit naming, structured tool results, deferred tool loading, hosted vs client tools, connector code-execution pattern.references/context-trust-labels.md— trusted / semi_trusted / untrusted labels + verbatim boundary statement; prompt-injection defense.references/agent-budgets.md— 10 mandatory budget types every agent loop must declare.references/agent-evals.md— 13 eval categories + 13 adversarial test cases + when to add regression evals.references/agent-observability.md— 16 trace fields per model call, 7-question audit, 6-step incident response.references/agentic-rag-model-policy.md— self-improving agentic RAG state, specialist roles, evaluation vectors, Pareto selection, OpenAI model/effort policy, and Programmatic Tool Calling adoption gates.references/agent-plan-artifact.md— planning mode, plan artifact format (10 fields), plan-validate-execute.references/agent-approval-records.md— approval request/result JSON schemas, scope/expiration, no self-approval.references/agent-streaming.md— buffering for incremental tool calls when stream=True; abort handling; output guardrail modes.references/agent-event-model.md— 13 typed events for harness state persistence (replay/audit/compaction/evals).references/agent-skill-install-checklist.md— pre/during/post install + audit + incident response for 3rd-party skills.
Source: distilled from the agents-best-practices skill (Denis Sergeevitch, MIT) + Anthropic harness-design engineering. Read the specific reference before applying — do not work from this index alone.