Reopen a closed board. Use this tool to unarchive a previously archived board.
AI agents use reopen_board to create or update resources in Trello — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Trello environment.
The tool restores a board to active status, which is a reversible state change (Write). It is not destructive since archiving/unarchiving is not permanent deletion. Severity is medium because unintended board reopening could affect team workflows and board visibility, but the action is recoverable by re-archiving.
From the tool's definition Tool description states 'Reopen a closed board' and 'unarchive a previously archived board' — this modifies board state by reversing an archive action.
Documented attack patterns abuse exactly the kind of access reopen_board gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Trello, and nothing reaches the server without passing your rules. This is the rule we recommend for reopen_board:
{
"version": "1",
"default": "deny",
"tools": {
"reopen_board": {
"limits": [
{
"counter": "reopen_board_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}reopen_board 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.
Reopen a closed board. Use this tool to unarchive a previously archived board. It is categorised as a Write tool in the Trello MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Trello MCP server in PolicyLayer and add a rule for reopen_board: 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 Trello. Nothing to install.
reopen_board 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 reopen_board 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 reopen_board. 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.
reopen_board is provided by the Trello MCP server (v4lheru/trello-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Trello, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
76 Trello tools catalogued and risk-classified — across an index of 43,000+ MCP servers.