Modifies the fields of an existing note.
AI agents use updateNoteFields to create or update resources in Anki — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Anki environment.
This tool modifies existing data (note fields) in a way that can be undone or changed later. It does not delete data irreversibly, does not execute arbitrary code, and does not involve financial transactions. The 'medium' severity reflects that a misbehaving agent could alter flashcard content across decks, but such changes are reversible through additional updates or manual correction.
From the tool's definition Tool name 'updateNoteFields' and description 'Modifies the fields of an existing note' indicate a reversible data modification operation on Anki flashcard content.
Documented attack patterns abuse exactly the kind of access updateNoteFields gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Anki, and nothing reaches the server without passing your rules. This is the rule we recommend for updateNoteFields:
{
"version": "1",
"default": "deny",
"tools": {
"updateNoteFields": {
"limits": [
{
"counter": "updatenotefields_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}updateNoteFields 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.
Free to start. No card required.
Modifies the fields of an existing note. It is categorised as a Write tool in the Anki MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Anki MCP server in PolicyLayer and add a rule for updateNoteFields: 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 Anki. Nothing to install.
updateNoteFields 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 updateNoteFields 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 updateNoteFields. 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.
updateNoteFields is provided by the Anki MCP server (ujisati/anki-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Anki, 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.
40 Anki tools catalogued and risk-classified — across an index of 43,000+ MCP servers.