This record as markdown: /tools/io-github-devopam-mcpg/open-cursor.md
What open_cursor does on Mcpg
AI agents invoke open_cursor to trigger actions in Mcpg. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call: builds kicked off, notifications sent, workflows started.
Why open_cursor is rated High
A cursor in PostgreSQL opens a handle for iterating over query results, which involves executing a database query. On a PostgreSQL server, opening a cursor typically requires executing SQL, which may include arbitrary or complex queries. Given the empty description, confidence is reduced, but the most likely interpretation is Execute-level risk (running a SQL query).
From the tool's definition Tool name: 'open_cursor'; description is empty/uninformative. Context: production-grade PostgreSQL MCP server with sibling tools involving query plans, policies, and analysis.
Attacks that exploit this kind of access
The rule that runs open_cursor safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Mcpg, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For open_cursor, this is the rule to start with:
open_cursor stays usable, but rate-capped: a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect Mcpg, apply this rule, and every open_cursor call is checked against it from then on.
Questions about open_cursor
open_cursor is a execute tool on the Mcpg MCP server. It is categorised as a Execute tool in the Mcpg MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Mcpg MCP server in PolicyLayer and add a rule for open_cursor: 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 Mcpg. Nothing to install.
open_cursor is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the open_cursor 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 open_cursor. 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.
open_cursor is provided by the Mcpg MCP server (pypi:mcpg). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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