AI agents invoke start_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 executes a real-time communication action with external parties. It initiates calls to other users, which is an operation that has immediate side effects and depends entirely on the arguments provided (who to call, what type of call). While not destructive or financial, it fits the Execute category as it triggers external operations.
From the tool's definition Tool name 'start_call' and description '发起语音/视频通话' (initiate voice/video call) indicates the tool triggers external communication operations (voice or video calls) whose effects depend on arguments (target user, call type).
Documented attack patterns abuse exactly the kind of access start_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 start_call:
{
"version": "1",
"default": "deny",
"tools": {
"start_call": {
"limits": [
{
"counter": "start_call_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}start_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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发起语音/视频通话. 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 start_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.
start_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 start_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 start_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.
start_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.