diff --git a/scripts/src/platform-infra-observability/options.ts b/scripts/src/platform-infra-observability/options.ts
index f738a9a0..2fc345bb 100644
--- a/scripts/src/platform-infra-observability/options.ts
+++ b/scripts/src/platform-infra-observability/options.ts
@@ -37,7 +37,7 @@ export function observabilityHelp(): Record<string, unknown> {
       "bun scripts/cli.ts platform-infra observability status --target D601 [--full|--raw]",
       "bun scripts/cli.ts platform-infra observability status --target D518 [--full|--raw]",
       "bun scripts/cli.ts platform-infra observability validate --target D518 [--full|--raw]",
-      "bun scripts/cli.ts platform-infra observability trace --target D518 --trace-id <traceId> [--grep provider-stream-disconnected] [--limit 40] [--full|--raw]",
+      "bun scripts/cli.ts platform-infra observability trace <traceId> --target D518 [--grep provider-stream-disconnected] [--limit 40] [--full|--raw]",
       "bun scripts/cli.ts platform-infra observability search --target D518 --grep 'no rollout found' [--lookback-minutes 360] [--candidate-limit 80] [--limit 20] [--full|--raw]",
       "bun scripts/cli.ts platform-infra observability search --target JD01 --grep opencode.proxy.stream.start --lookback-minutes 30 --limit 20",
       "bun scripts/cli.ts platform-infra observability search --target JD01 --grep opencode.proxy.sse.directory_rewrite_enabled --lookback-minutes 30 --limit 20",
@@ -113,13 +113,17 @@ export function parseTraceOptions(args: string[]): TraceOptions {
   let traceId: string | null = null;
   let grep: string | null = null;
   let limit = 40;
+  const assignTraceId = (value: string) => {
+    if (!/^[0-9a-fA-F]{32}$/u.test(value)) throw new Error("trace id must be a 32-character OpenTelemetry trace id encoded as hex");
+    if (traceId !== null) throw new Error("observability trace accepts exactly one trace id, either positionally or through --trace-id");
+    traceId = value;
+  };
   for (let index = 0; index < args.length; index += 1) {
     const arg = args[index];
     if (arg === "--trace-id") {
       const value = args[index + 1];
       if (value === undefined || value.startsWith("--")) throw new Error("--trace-id requires a value");
-      if (!/^[0-9a-fA-F]{32}$/u.test(value)) throw new Error("--trace-id must be a 32-character OpenTelemetry trace id encoded as hex");
-      traceId = value;
+      assignTraceId(value);
       index += 1;
     } else if (arg === "--grep") {
       const value = args[index + 1];
@@ -133,6 +137,8 @@ export function parseTraceOptions(args: string[]): TraceOptions {
       if (!Number.isInteger(parsed) || parsed < 1 || parsed > 500) throw new Error("--limit must be an integer from 1 to 500");
       limit = parsed;
       index += 1;
+    } else if (!arg.startsWith("--")) {
+      assignTraceId(arg);
     } else {
       commonArgs.push(arg);
       if (arg === "--target") {
diff --git a/scripts/src/platform-infra/entry.ts b/scripts/src/platform-infra/entry.ts
index bd711d17..9e2771b2 100644
--- a/scripts/src/platform-infra/entry.ts
+++ b/scripts/src/platform-infra/entry.ts
@@ -438,7 +438,7 @@ export function platformInfraHelp(): unknown {
       "bun scripts/cli.ts platform-infra observability apply --target D601 --confirm",
       "bun scripts/cli.ts platform-infra observability status --target D601",
       "bun scripts/cli.ts platform-infra observability validate --target D601",
-      "bun scripts/cli.ts platform-infra observability trace --target D601 --trace-id <traceId> [--grep text] [--limit 40] [--full|--raw]",
+      "bun scripts/cli.ts platform-infra observability trace <traceId> --target D601 [--grep text] [--limit 40] [--full|--raw]",
       "bun scripts/cli.ts platform-infra observability search --target D601 --grep 'no rollout found' [--lookback-minutes 360] [--candidate-limit 80] [--limit 20]",
       "bun scripts/cli.ts platform-infra observability diagnose-code-agent --target D601 --business-trace-id <trc_...> [--full|--raw]",
       "bun scripts/cli.ts platform-infra observability diagnose-code-agent --target D601 --run-id <run_...> [--command-id <cmd_...>] [--runner-job-id <rjob_...>]",