Subagents

In our earlier architecture deep-dives, we examined how Attention Dilution cripples autonomous coding agents. As context windows swell past tens of thousands of tokens with terminal traces, compiler diagnostics, and speculative file edits, an agent’s attention mechanism degrades. Critical system constraints, architectural decision records (ADRs), and testing invariants drift into the periphery, leading to hallucinations, ignored instructions, and silent error suppression. To solve this in Google Antigravity, we built the Antigravity Attention Guard Plugin—a deterministic runtime firewall that enforces subagent delegation, sandboxed tool execution, and cryptographic ledger tracking. ...

In our previous discussions on autonomous engineering, we explored the phenomenon of Attention Dilution—the silent degradation of instruction-following fidelity as context windows swell past tens of thousands of tokens. While modern frontier models boast context windows of 1M+ tokens, attention mechanisms remain vulnerable to informational entropy. As terminal logs, stack traces, and code diffs accumulate, system prompt constraints drift out of the model’s active attention focus. When left unchecked, agents exhibit architectural amnesia: they bypass project-level Architecture Decision Records (ADRs), run uncompressed shell commands that flood context, guess port allocations, or skip verification steps. ...