AI agents use update_item to create or update resources in DMCP — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your DMCP environment.
This tool modifies game item data reversibly within an RPG context. It does not delete, execute code, move money, or perform irreversible operations. The blast radius is medium because malicious item updates could corrupt game progression or advantage player characters, but effects are reversible through subsequent updates or resets within the game's state management system.
From the tool's definition Tool name 'update_item' and description 'Update an item' indicate modification of game state data. The sibling tools (add_clue, add_combat_log, apply_status_effect, apply_theme_preset) all perform Write-class mutations to RPG game state.
Documented attack patterns abuse exactly the kind of access update_item gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and DMCP, and nothing reaches the server without passing your rules. This is the rule we recommend for update_item:
{
"version": "1",
"default": "deny",
"tools": {
"update_item": {
"limits": [
{
"counter": "update_item_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}update_item 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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Update an item. It is categorised as a Write tool in the DMCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the D MCP server in PolicyLayer and add a rule for update_item: 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 DMCP. Nothing to install.
update_item 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 update_item 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 update_item. 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.
update_item is provided by the D MCP server (shawnrushefsky/dmcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from DMCP, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
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204 DMCP tools catalogued and risk-classified — across an index of 43,000+ MCP servers.