Catches the mistakes coding agents repeat before they merge: a pull-request gate with no model call and no API key.
Short answer: Avoid dynamic user IDs or timestamps in metric labels. A user id as a metric label creates a new time series per user and floods the store.
Group: Observability and logging. Status: stable. Generated from the rule definitions; do not edit by hand.
Playground: https://brevio.pro/tools/agent-guard-playground?rule=R13.4
Metric label cardinality bounding: avoid dynamic user IDs or timestamps in metric labels.
A user id as a metric label creates a new time series per user and floods the store.
counter.inc({ userId });
counter.inc({ route });
A person can silence one finding with brevio-core: ignore R13.4 -- reason on the line or the line above. Without the reason it does not count. An agent cannot silence it: the agent hook and the MCP tools never honour the comment, and a pull request that adds one is reported until a reviewer allows it. Fixing the code is still the better answer.
To change what the rule flags, edit its definition in dev_rules.py or code_rules/__init__.py. That is a code change and is reviewed like one.