AI agents use send_reaction to create or update resources in Telegram MCP Complete — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Telegram MCP Complete environment.
Sending a reaction is a reversible write operation that creates new data (the reaction record) but does not execute arbitrary code, delete data, or move money. The severity is medium because widespread misuse could spam reactions across many messages or accounts, causing disruption, but the impact is limited to cosmetic message decorations rather than data destruction or financial harm.
From the tool's definition Tool name 'send_reaction' and description '对消息发送表情反应' (sends emoji reactions to messages) indicates creation of a reaction object/interaction on a message, which modifies message metadata and creates a new interaction record.
Documented attack patterns abuse exactly the kind of access send_reaction gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Telegram MCP Complete, and nothing reaches the server without passing your rules. This is the rule we recommend for send_reaction:
{
"version": "1",
"default": "deny",
"tools": {
"send_reaction": {
"limits": [
{
"counter": "send_reaction_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}send_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.
对消息发送表情反应. It is categorised as a Write tool in the Telegram MCP Complete MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Telegram MCP Complete MCP server in PolicyLayer and add a rule for send_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 Telegram MCP Complete. Nothing to install.
send_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 send_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 send_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.
send_reaction is provided by the Telegram MCP Complete MCP server (you922/telegram-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Telegram MCP Complete, 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.
153 Telegram MCP Complete tools catalogued and risk-classified — across an index of 43,000+ MCP servers.