Lists tables in the instance by querying the system's metadata table (sys_db_object).
AI agents call list_available_tables to retrieve information from Snow without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool performs metadata discovery by querying sys_db_object, which is a read-only information retrieval operation. It returns information about available tables but does not create, modify, delete, or execute any operations. The blast radius of misuse is minimal, as it only exposes schema information that would typically be available to authenticated users in a ServiceNow instance.
From the tool's definition Tool description explicitly states it 'Lists tables in the instance by querying the system's metadata table (sys_db_object)' — a pure retrieval operation with no data modification, deletion, or side effects.
Documented attack patterns abuse exactly the kind of access list_available_tables gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Snow, and nothing reaches the server without passing your rules. This is the rule we recommend for list_available_tables:
{
"version": "1",
"default": "deny",
"tools": {
"list_available_tables": {}
}
}list_available_tables is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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Lists tables in the instance by querying the system's metadata table (sys_db_object). It is categorised as a Read tool in the Snow MCP Server, which means it retrieves data without modifying state.
Register the Snow MCP server in PolicyLayer and add a rule for list_available_tables: 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 Snow. Nothing to install.
list_available_tables 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 list_available_tables 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 list_available_tables. 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.
list_available_tables is provided by the Snow MCP server (shunyaai/snow-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Snow, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
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88 Snow tools catalogued and risk-classified — across an index of 43,000+ MCP servers.