Update existing rows in a PostgreSQL table that match specified conditions. Use this tool to modify data that already exists in the database. Example: Update the status to
AI agents use update_entry to create or update resources in PostgreSQL MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your PostgreSQL MCP Server environment.
This tool modifies existing database records, which is a Write operation (reversible data change). It is not Destructive because updates are not irreversible deletions. Severity is high because an AI agent could inadvertently modify large datasets or critical business data if given broad row-matching conditions, but the reversible nature of updates prevents it from being critical.
From the tool's definition Tool description states 'Update existing rows in a PostgreSQL table that match specified conditions. Use this tool to modify data that already exists in the database.' The verb 'modify' and 'update' confirm data alteration capability.
Documented attack patterns abuse exactly the kind of access update_entry gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and PostgreSQL MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for update_entry:
{
"version": "1",
"default": "deny",
"tools": {
"update_entry": {
"limits": [
{
"counter": "update_entry_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}update_entry stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.
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Update existing rows in a PostgreSQL table that match specified conditions. Use this tool to modify data that already exists in the database. Example: Update the status to. It is categorised as a Write tool in the PostgreSQL MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the PostgreSQL MCP Server MCP server in PolicyLayer and add a rule for update_entry: 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 PostgreSQL MCP Server. Nothing to install.
update_entry is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the update_entry 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 update_entry. 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.
update_entry is provided by the PostgreSQL MCP Server MCP server (vignesh-codes/ai-agents-mcp-pg). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from PostgreSQL MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
6 PostgreSQL MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.