AI agents use add_todo to create or update resources in Things 3 MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Things 3 MCP Server environment.
Creating a new todo task is a reversible write operation. The severity is medium because an AI agent injecting malicious or unwanted tasks could clutter a user's task management system, but the operation is undoable (tasks can be deleted). It does not meet the threshold for higher categories—it neither executes arbitrary code, permanently destroys data, nor moves money.
From the tool's definition Tool name 'add_todo' combined with server description stating 'task creation' and 'GTD workflow automation' indicates this tool creates new task entries.
Documented attack patterns abuse exactly the kind of access add_todo gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Things 3 MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for add_todo:
{
"version": "1",
"default": "deny",
"tools": {
"add_todo": {
"limits": [
{
"counter": "add_todo_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}add_todo 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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add_todo. It is categorised as a Write tool in the Things 3 MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Things 3 MCP Server MCP server in PolicyLayer and add a rule for add_todo: 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 Things 3 MCP Server. Nothing to install.
add_todo 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_todo 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_todo. 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_todo is provided by the Things 3 MCP Server MCP server (rossshannon/things3-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 24 Things 3 MCP Server tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
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24 Things 3 MCP Server tools catalogued and risk-classified — across an index of 42,500+ MCP servers.