> ## Documentation Index > Fetch the complete documentation index at: https://docs.itellico.ai/llms.txt > Use this file to discover all available pages before exploring further. # Custom Action Troubleshooting > Diagnose authentication, payload, timeout, and response issues in custom API actions Use this page when a [Custom API Tool](/build/tools/custom-api-actions) is configured, but the live conversation does not behave the way you expect. Typical symptoms: * the tool never triggers * the API call fails * variables do not populate * the API succeeds, but the agent answers badly afterward ## Fast Triage Start here before changing multiple settings at once. 1. Confirm the tool is configured with the correct method, URL, and auth type. 2. Confirm your agent prompt references the tool by the exact configured name. 3. Confirm required variables are defined clearly. 4. Test the endpoint outside the agent with static values first. 5. Re-run the scenario and inspect the [conversation timeline](/manage/conversations/detail). ## Symptom: The Tool Never Triggers ### Likely causes * the tool name is too vague * the description does not tell the model what the tool is for * the prompt does not define when to use it * another tool overlaps with the same intent ### What to fix * rename the tool with a clear action-oriented name * improve the description * add explicit trigger guidance to your prompt * remove overlapping tools if possible ## Symptom: Authentication Fails ### Likely causes * wrong auth type * expired token * missing header or credential field * credentials entered in the wrong place ### What to fix * confirm the API expects Bearer, Basic, Header, or Body auth * retest in Postman or cURL using the same credentials * rotate the token if needed * move credentials out of the URL and into the proper auth field ## Symptom: Variables Are Missing Or Not Replacing ### Likely causes * wrong variable name * required variable was never collected * the contact record does not contain the expected field * the template syntax is wrong ### What to fix * check variable spelling exactly * confirm the field exists in the right source * use `{{variable_name}}` syntax consistently * add descriptions and examples so the model knows what to collect ## Symptom: The API Is Slow Or Times Out ### Likely causes * slow external system * unnecessary work inside the endpoint * the tool is being used for a task that should happen after the call ### What to fix * make the endpoint faster * reduce payload size * cache repeated reads when possible * move non-live work to [Webhooks](/accounts/webhooks) or [Post-Call Automation](/build/analytics/post-call-automation) ## Symptom: The API Succeeds But The Agent Responds Poorly This is often a prompt problem, not an API problem. ### Likely causes * the tool description does not explain what the result means * the prompt does not tell the agent how to use the result * the API response is too noisy or inconsistent ### What to fix * simplify the response shape * return only the fields the conversation needs * update the prompt with clear post-tool instructions ### Example ```text theme={null} After using 'Lookup Order Status': - If status is shipped, tell the caller the order is on the way. - If status is delayed, apologize and offer next steps. - If the order is not found, ask the caller to confirm the order number. ``` ## Symptom: The Tool Works In Postman But Not In The Agent ### Likely causes * template variables are producing different values than your manual test * the model is collecting bad values from the caller * the endpoint works only for one very specific payload shape ### What to fix * test first with static values inside the tool configuration * then replace one field at a time with live variables * compare the agent-triggered payload with the known-good payload ## What To Check In The Conversation Timeline Open the conversation detail and inspect: * whether the tool fired at all * which step failed * whether variables were collected correctly * how long the tool took * what the agent did immediately after the tool returned The timeline is often the fastest way to separate: * prompt issues * variable issues * endpoint issues * post-tool response issues ## A Reliable Test Sequence 1. Test the endpoint directly outside the platform. 2. Test the tool with static values. 3. Replace one static field with one live variable. 4. Trigger the tool in a controlled test conversation. 5. Review the conversation timeline. 6. Adjust the prompt only after the API layer is known-good. ## Next Steps Configure the tool itself Understand where variables and values come from Validate the tool in a repeatable test loop Troubleshoot tools and webhooks