AI agents use update_record_assignees to create or update resources in Kintone MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Kintone MCP Server environment.
This tool creates or modifies data reversibly by changing the assignee field on Kintone records. Unlike destructive operations (which would delete records), this updates assignee metadata, making it a Write action. Severity is medium because misuse could redirect work inappropriately, potentially disrupting workflows or assigning sensitive tasks to wrong users, but the change itself is auditable and reversible.
From the tool's definition Tool description states 'update_record_assignees' and 'kintoneレコードの作業者を更新します（プロセス管理）' - this updates assignees on a record within process management, which modifies metadata associated with records.
Documented attack patterns abuse exactly the kind of access update_record_assignees gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Kintone MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for update_record_assignees:
{
"version": "1",
"default": "deny",
"tools": {
"update_record_assignees": {
"limits": [
{
"counter": "update_record_assignees_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}update_record_assignees 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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kintoneレコードの作業者を更新します（プロセス管理）. It is categorised as a Write tool in the Kintone MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Kintone MCP Server MCP server in PolicyLayer and add a rule for update_record_assignees: 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 Kintone MCP Server. Nothing to install.
update_record_assignees 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_record_assignees 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_record_assignees. 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_record_assignees is provided by the Kintone MCP Server MCP server (r3-yamauchi/kintone-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Kintone 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.
70 Kintone MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.