List all categories. Use categories to classify transactions (e.g. Groceries, Rent, Entertainment).
AI agents call firefly_list_categories to retrieve information from Firefly III MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves and queries existing financial category data without creating, modifying, deleting, or moving any money. It is purely informational and safe to expose to an AI agent. Listing categories carries minimal risk as it reveals only the user's own categorization scheme, not sensitive transaction amounts or balances.
From the tool's definition Tool name is 'firefly_list_categories' and description states 'List all categories' — a retrieval operation with no modification or side effects.
Attacks that exploit this kind of access
List all categories. Use categories to classify transactions (e.g. Groceries, Rent, Entertainment). It is categorised as a Read tool in the Firefly III MCP Server MCP Server, which means it retrieves data without modifying state.
Register the Firefly III MCP Server MCP server in PolicyLayer and add a rule for firefly_list_categories: 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 Firefly III MCP Server. Nothing to install.
firefly_list_categories is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the firefly_list_categories 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 firefly_list_categories. 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.
firefly_list_categories is provided by the Firefly III MCP Server MCP server (przbadu/firefly-iii-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
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