AI agents use complete_task to create or update resources in Google Tasks MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Google Tasks MCP Server environment.
This tool modifies data (task completion status) but does so reversibly—toggling completion status can be undone by toggling it again. It is not destructive (does not delete), not financial, and not Execute (does not run arbitrary code). It is classified as Write because it creates or modifies data reversibly.
From the tool's definition The tool 'complete_task' toggles the completion status of a task, modifying task state. The description states it changes (toggles) a task's completion status, which is a reversible state modification.
Documented attack patterns abuse exactly the kind of access complete_task gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Google Tasks MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for complete_task:
{
"version": "1",
"default": "deny",
"tools": {
"complete_task": {
"limits": [
{
"counter": "complete_task_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
} complete_task 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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Toggle the completion status of a task. It is categorised as a Write tool in the Google Tasks MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Google Tasks MCP Server MCP server in PolicyLayer and add a rule for complete_task: 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 Google Tasks MCP Server. Nothing to install.
complete_task 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 complete_task 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 complete_task. 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.
complete_task is provided by the Google Tasks MCP Server MCP server (mstfe/mcp-google-tasks). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Google Tasks MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
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4 Google Tasks MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.