fix(tool-bash): handle unavailable spill paths

packages/tool-bash/src/index.ts

@@ -316,7 +316,7 @@ export function apply(ctx: Context): void {
     description: 'Execute a bash command (`bash -c`) and return its stdout/stderr. '
       + 'Each call runs in a fresh shell: no state (cwd, variables, functions) persists between calls — '
       + 'pass `workdir` instead of using `cd`. Non-zero exits are reported as `[exit code: N]`. '
-      + 'Long output is truncated to its tail; the full output is saved to a file whose path is reported. '
+      + 'Long output is truncated to its tail; the full output is saved to a file whose path is reported when available. '
       + 'Set `run_in_background: true` for long-running commands: the call returns a task id immediately; '
       + 'poll it with `bash_output` and stop it with `bash_kill`.',
     parameters: {
@@ -377,7 +377,8 @@ export function apply(ctx: Context): void {
       let text = read.delta.length > 0 ? read.delta : '(no new output)'
       if (read.lossy) {
         const paths = [read.stdoutSpillPath, read.stderrSpillPath].filter((p): p is string => p !== undefined)
-        text += `\n[some output was dropped from memory; full output: ${paths.join(', ')}]`
+        const fullOutput = paths.length > 0 ? paths.join(', ') : '(unavailable)'
+        text += `\n[some output was dropped from memory; full output: ${fullOutput}]`
       }
       text += `\n${statusLine(read.task)}`
       return Promise.resolve([{ type: 'text', text }])