AI agents call list_instances to retrieve information from Mcp Oceanbase without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves information about OceanBase instances without performing any side effects, creating, modifying, or deleting data. It is a straightforward informational query operation, consistent with the Read category. The low severity reflects minimal blast radius if misused by an AI agent—listing instances poses no direct risk to system integrity or data.
From the tool's definition Tool name 'list_instances' and description 'list oceanbase instances' indicate a query/retrieval operation with no data modification, deletion, or execution of commands.
Documented attack patterns abuse exactly the kind of access list_instances gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Mcp Oceanbase, and nothing reaches the server without passing your rules. This is the rule we recommend for list_instances:
{
"version": "1",
"default": "deny",
"tools": {
"list_instances": {}
}
}list_instances is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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list oceanbase instances. It is categorised as a Read tool in the Mcp Oceanbase MCP Server, which means it retrieves data without modifying state.
Register the Mcp Oceanbase MCP server in PolicyLayer and add a rule for list_instances: 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 Mcp Oceanbase. Nothing to install.
list_instances 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_instances 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_instances. 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_instances is provided by the Mcp Oceanbase MCP server (oceanbase/awesome-oceanbase-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 134 Mcp Oceanbase tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
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134 Mcp Oceanbase tools catalogued and risk-classified — across an index of 42,500+ MCP servers.