AI agents use add_note_type_field to create or update resources in Anki MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Anki MCP Server environment.
This tool creates or modifies note type schemas by adding fields, which is a reversible write operation. While it modifies the data structure of note types (affecting all cards using that type), the change can be undone by removing the field. This is not destructive (the field addition itself doesn't delete data), not execute (no code/commands run), and not financial.
From the tool's definition The tool name 'add_note_type_field' and description 'Adds a new field to a note type' indicate a modification operation that creates a new field structure within an Anki note type.
Documented attack patterns abuse exactly the kind of access add_note_type_field gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Anki MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for add_note_type_field:
{
"version": "1",
"default": "deny",
"tools": {
"add_note_type_field": {
"limits": [
{
"counter": "add_note_type_field_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}add_note_type_field 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.
Adds a new field to a note type. It is categorised as a Write tool in the Anki MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Anki MCP Server MCP server in PolicyLayer and add a rule for add_note_type_field: 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 MCP Server. Nothing to install.
add_note_type_field 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 add_note_type_field 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 add_note_type_field. 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.
add_note_type_field is provided by the Anki MCP Server MCP server (nietus/anki-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 22 Anki MCP Server tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
22 Anki MCP Server tools catalogued and risk-classified — across an index of 42,500+ MCP servers.