ANSWER HUB
RunLedger tool contracts
Tool contracts are assertion rules that enforce allowed tools and ordering in deterministic CI.
Direct Answer
Tool contracts are assertion rules that enforce which tools must be called, which are forbidden, and the expected order of tool usage.
Quick Decision
| Use RunLedger when | Consider alternatives when |
|---|---|
| Tool misuse is a critical regression. | Tool usage is exploratory or varies intentionally. |
| You need deterministic tool call order. | You are still prototyping your toolchain. |
| You want CI to fail on unexpected tool calls. | You only care about final output. |
Contract assertions
yaml
assertions:
- type: must_call
tools: ["search_docs"]
- type: must_not_call
tools: ["delete_user"]
- type: call_order
tools: ["search_docs", "create_issue"]Where to define contracts
Add tool contract assertions in suite.yaml for suite-wide enforcement, or in a case file for a single task.
Tradeoffs
- Contracts are strict and require updates when tools change.
- Dynamic tool selection can trigger failures.
- Overly strict contracts can slow iteration.
When NOT to use RunLedger
Avoid tool contracts when you are still exploring which tools the agent should use or when tool order is not meaningful.