This record as markdown: /tools/karbassi-slack-mcp/reminders-complete.md
What reminders_complete does on Slack
AI agents use reminders_complete to create or update resources in Slack, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Slack environment.
Why reminders_complete is rated Medium
This tool modifies reminder state by marking it as complete, which is a reversible write operation. It does not delete data (would be Destructive), execute arbitrary code (would be Execute), move money (would be Financial), or merely read data (would be Read).
From the tool's definition Tool name 'reminders_complete' and description 'Mark a reminder as complete' indicate a state-change operation that modifies reminder data.
Attacks that exploit this kind of access
The rule that runs reminders_complete safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Slack, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For reminders_complete, this is the rule to start with:
reminders_complete 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.
The button opens the PolicyLayer dashboard: create your workspace, connect Slack, apply this rule, and every reminders_complete call is checked against it from then on.
Questions about reminders_complete
Mark a reminder as complete. It is categorised as a Write tool in the Slack MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Slack MCP server in PolicyLayer and add a rule for reminders_complete: 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 Slack. Nothing to install.
reminders_complete 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 reminders_complete 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 reminders_complete. 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.
reminders_complete is provided by the Slack MCP server (karbassi/slack-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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