agent-runtime-patternslisted

# Agent Runtime Patterns ## When to use - Optimizing a slow or over-spending agent loop (too many tool calls, high token use). - Designing multi-agent orchestration topology for a new workflow. - Managing MCP session lifecycle for experimental data-layer sessions. - Reducing redundant search or file-read loops. ## Core Patterns | Pattern | Use when | Avoid when | |---|---|---| | **Direct execution** | Single agent, clear scope, no subagent benefits | Task genuinely requires parallel sub-agents or specialized routing | | **Routing** | Input type determines which specialized agent to invoke | Agents share context and can't be isolated | | **Chaining** | Output of A is strict input of B | Agents need to share partial context | | **Orchestrator-worker** | Parallel independent subtasks with a coordinator | Tasks are tightly coupled or sequential | | **Agents-as-tools** | Callable child agent inside a parent's tool loop | The child needs user interaction | ## Knowledge Cards A **card** is a compact, high-signal instruction block — typically 3–10 lines — for a specific operation. Cards are preferable to loading full documentation into context. Good card: step sequence + key constraint + example invocation. Bad card: copied README sections, multiple unrelated topics in one block. Pack cards for the current task only. Swap cards between phases rather than accumulating them. ## Workflow 1. **Identify the bottleneck** — measure before optimizing: count tool calls, token usage,