refactor: unify tool reason requirements

.opencode/tools/publish_execution_plan.ts

@@ -1,3 +1,4 @@
+import { toolReason } from "../tool-reason.js";
 import { tool } from "../tool.js";
 import { getInternalBridgeConfig } from "../internalBridge.js";
 import { newExecutionPlanSchema } from "../../src/routes/executionPlan.js";
@@ -8,7 +9,7 @@ export default tool({
     request_id: tool.schema.string().describe("Stable UUID idempotency key for this plan revision"),
     schema: tool.schema.enum(["execution-plan@2"]),
     title: tool.schema.string(),
-    reason: tool.schema.string().describe("Why the plan or node status changed"),
+    reason: toolReason.max(1000).describe("One concise sentence explaining why the plan or node status changed."),
     nodes: tool.schema.array(tool.schema.object({
       id: tool.schema.string(), title: tool.schema.string(),
       status: tool.schema.enum(["pending", "running", "waiting", "completed", "failed", "skipped", "cancelled"]),