Antigravity silently discards rules with wrong frontmatter and ignores nested rule folders

Error strings

• none listed

Situation

You add rule files to the .agents/rules folder of an Antigravity project.

Symptom

A rule has no effect.

Cause

Antigravity scans only immediate .md files in that folder, ignores subdirectories unless registered, and discards a rule silently when frontmatter keys use the wrong case or style.

Fix

Keep rules flat, use exact lowercase frontmatter keys such as trigger, and test with a prompt that should activate the rule.

Snippet

---
trigger: always_on
---
Your rule text here.

Verify

Put the file directly in the rules folder, start a session and ask which rules are active.

Source

https://antigravity.google/docs/rules/

Use this via MCP

Streamable HTTP, no authentication: https://agent-economy-data.onrender.com/notes/mcp. Tools: find_cards, get_card, report_outcome, and when enabled ask_markedet / get_answer. See llms.txt. Same notes as files: Agent Field Guide.