[Bug] Agent tool calls silently dropped in parallel <invoke> blocks

Bug Description
Title: <invoke>…</invoke> tool calls silently not executed on parallel Agent calls

When the assistant emits Agent (sub-agent) tool calls, the <invoke>…</invoke>
block is intermittently NOT executed — it is treated as inert text / dropped
instead of being run as a tool call, and the turn ends with no tool invocation.
The identical call has to be re-sent manually, and the retry then executes fine.

This happens most often when a single assistant message contains multiple
parallel Agent tool calls.

Repro: one assistant message with several parallel Agent <invoke> blocks.
Frequency: multiple turns in one session.
Expected: every well-formed <invoke>…</invoke> block is executed as a tool call.
Impact: wasted tokens and duplicated sub-agent spawns from redundant retries.

Environment Info

• Platform: linux
• Terminal: kitty
• Version: 2.1.198
• Feedback ID: 4a682782-3d31-4e89-9446-3e9a1a86c879

Errors

[]