AI agents invoke discard_call to trigger actions in Telegram MCP Complete. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.
This tool actively rejects/discards an incoming call, which is an external operation with real-time side effects (the caller is notified the call was rejected). It is not purely a read, nor does it delete data or move money. It triggers an action on the Telegram platform, classifying it as Execute.
From the tool's definition discard_call — '拒绝来电' means 'reject incoming call', triggering an external telephony operation on Telegram
Documented attack patterns abuse exactly the kind of access discard_call 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 discard_call:
{
"version": "1",
"default": "deny",
"tools": {
"discard_call": {
"limits": [
{
"counter": "discard_call_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}discard_call stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.
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拒绝来电. It is categorised as a Execute tool in the Telegram MCP Complete MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Telegram MCP Complete MCP server in PolicyLayer and add a rule for discard_call: 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.
discard_call is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the discard_call 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 discard_call. 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.
discard_call 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.