AI agents use discord_add_reaction to create or update resources in Sage MCP — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Sage MCP environment.
Adding a reaction modifies Discord message state by appending a reaction, making this a Write operation rather than Read. The severity is medium because while reactions are reversible and low-impact individually, an AI agent could spam reactions across many messages to disrupt communication or manipulate user engagement.
From the tool's definition Tool name 'discord_add_reaction' and description 'Add a reaction emoji to a message' indicate creation of a new reaction (emoji) on an existing Discord message, which modifies message state.
Documented attack patterns abuse exactly the kind of access discord_add_reaction gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Sage MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for discord_add_reaction:
{
"version": "1",
"default": "deny",
"tools": {
"discord_add_reaction": {
"limits": [
{
"counter": "discord_add_reaction_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}discord_add_reaction 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.
Add a reaction emoji to a message. It is categorised as a Write tool in the Sage MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Sage MCP server in PolicyLayer and add a rule for discord_add_reaction: 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 Sage MCP. Nothing to install.
discord_add_reaction 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 discord_add_reaction 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 discord_add_reaction. 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.
discord_add_reaction is provided by the Sage MCP server (sagemcp/sagemcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 359 Sage MCP tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
359 Sage MCP tools catalogued and risk-classified — across an index of 42,500+ MCP servers.