### Answer When your bot hangs up immediately after calling someone, you should check the disconnection reason to diagnose the issue. You can check this through the Retell Dashboard or by using the get-call API endpoint [(1) ]() . Common reasons for immediate disconnection include : Not Connected Issues: -

dial_busy

- the number dialed is busy -

dial_failed

- dialing failed with no or unknown sip error code -

dial_no_answer

- the number dialed did not answer -

invalid_destination

- the number dialed is invalid (can be due to spaces or invalid characters, or your telephony provider requiring specific format like e.164) -

marked_as_spam

- the number dialed is marked as spam Configuration Issues: -

voicemail_reached

- if your AI agent is configured with voicemail settings and voicemail is reached -

ivr_reached

- if your AI agent is configured to hang up when encountering an IVR system Error Issues: -

error_llm_websocket_open

- LLM websocket did not open between Retell server and your backend (likely because the Custom LLM URL is incorrect or your LLM server is unreachable) To prevent immediate hangups, check your agent's configuration for

voicemail_option

and

ivr_option

settings [(2) ]() [(3) ]() [(4) ]() . You can also adjust

begin_message_delay_ms

(controls delay before agent speaks) and

ring_duration_ms

(controls ring duration for outbound calls) .

​ To learn more, see the sources I considered: [[1] Debug call disconnection](https://docs.retellai.com/reliability/debug-call-disconnect) [[2] Update Voice Agent](https://docs.retellai.com/api-references/update-agent) [[3] Get Agent Versions](https://docs.retellai.com/api-references/get-agent-versions) [[4] List Voice Agents](https://docs.retellai.com/api-references/list-agents) ​

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.

### Answer Based on the issue you're describing (bot calling the end_call tool immediately after greeting) , this is typically a prompting issue where the AI is interpreting your instructions too broadly [(1) ]() . Check your prompt for these common triggers: 1. Broad end-call instructions - Remove phrases like "End every call with care" or similar statements that don't specify when to end the call. The AI may interpret this as ending every call . 2. Vague spam/suspicious call handling - If your prompt says something like "Politely end the call" for suspicious calls without clear criteria for what constitutes spam, the AI may trigger this prematurely . How to fix it: - Be specific about when to call the end_call function. Instead of "end every call with care," specify the exact conditions (e.g., "only after the customer confirms they have no more questions") . - Define clear criteria for any automated hang-up scenarios (spam detection, voicemail, etc.) . - Review your call logs to see the exact arguments passed to the end_call function - this will show you what the AI "thought" justified ending the call . Example from a resolved case: A user had "End every call with care" in their prompt, which caused the agent to hang up on every call. After removing this phrase and being more specific about end conditions, the issue was resolved . Check your agent's prompt and function descriptions for any broad end-call language and make them more conditional and specific.

​ To learn more, see the sources I considered: [[1] Agent Hangs Up After Greeting — No User Interaction](https://discord.com/channels/1186424376300679209/1426275379307610274) ​

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.