Pull canceled subscriptions directly from a Postgres or MySQL database and analyze them for churn patterns. Requires POSTGRES_URL or MYSQL_URL env var (use a read-only database user , see retentioncheck.com/integrations for the exact SQL to create one). You describe your schema in plain arguments...
Risk signalsHigh parameter count (14 properties)
Part of the RetentionCheck server.
Free to start. No card required.
AI agents call analyze_sql_churn to retrieve information from RetentionCheck without modifying any data. This is common in research, monitoring, and reporting workflows where the agent needs context before taking action. Because read operations don't change state, they are generally safe to allow without restrictions -- but you may still want rate limits to control API costs.
Even though analyze_sql_churn only reads data, uncontrolled read access can leak sensitive information or rack up API costs. An agent caught in a retry loop could make thousands of calls per minute. A rate limit gives you a safety net without blocking legitimate use.
Read-only tools are safe to allow by default. No rate limit needed unless you want to control costs.
{
"version": "1",
"default": "deny",
"tools": {
"analyze_sql_churn": {}
}
}See the full RetentionCheck policy for all 5 tools.
These attack patterns abuse exactly the kind of access analyze_sql_churn gives an agent. Each links to the full case and the policy that stops it:
Other read tools across the catalogue. The same approach applies to each: allow, with a rate cap to control cost.
Pull canceled subscriptions directly from a Postgres or MySQL database and analyze them for churn patterns. Requires POSTGRES_URL or MYSQL_URL env var (use a read-only database user , see retentioncheck.com/integrations for the exact SQL to create one). You describe your schema in plain arguments (table, cancelled_at_column, reason_column, etc.) and the tool generates a safe parameterized SELECT query. Includes plan MRR, sub age, and schema-mismatch detection with actionable errors. Defaults to last 90 days.. It is categorised as a Read tool in the RetentionCheck MCP Server, which means it retrieves data without modifying state.
Register the RetentionCheck MCP server in PolicyLayer and add a rule for analyze_sql_churn: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches RetentionCheck. Nothing to install.
analyze_sql_churn is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the analyze_sql_churn rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for analyze_sql_churn. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
analyze_sql_churn is provided by the RetentionCheck MCP server (@retentioncheck/mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 5 RetentionCheck tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
4,600+ MCP servers and 31,000+ tools scanned and risk-classified.