AI agents use update to create or update resources in Memory-Plus — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Memory-Plus environment.
The tool modifies persistent memory state but does not irreversibly delete data (unlike 'delete' sibling), does not execute external code (unlike Execute category), and does not move money (unlike Financial). Update operations are reversible writes.
From the tool's definition Tool name is 'update' on a memory store server; sibling tools include 'record', 'delete', 'retrieve', and 'delete_memory', establishing the server's purpose as persistent data modification.
Documented attack patterns abuse exactly the kind of access update gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Memory-Plus, and nothing reaches the server without passing your rules. This is the rule we recommend for update:
{
"version": "1",
"default": "deny",
"tools": {
"update": {
"limits": [
{
"counter": "update_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}update 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. It is categorised as a Write tool in the Memory-Plus MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Memory-Plus MCP server in PolicyLayer and add a rule for update: 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 Memory-Plus. Nothing to install.
update 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 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. 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 is provided by the Memory-Plus MCP server (yuchen20/memory-plus). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 14 Memory-Plus tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
14 Memory-Plus tools catalogued and risk-classified — across an index of 42,500+ MCP servers.