# Troubleshooting Agents

Troubleshoot common issues with Agents.

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## MCP Connection Error

## Pipeline Tool Shows Validation Warnings

When you add a pipeline as a tool, deepset validates the pipeline before adding it. If the pipeline has non-fatal validation issues (warnings), the tool is still added to the Agent. The warnings are stored on the tool and are visible in the tool configuration.

Warnings do not prevent the tool from being used, but you should review them to make sure the pipeline behaves as expected. To inspect the warnings, open the tool configuration in the Agent's *Tools* panel.

If you see a hard validation error and the tool was not added, the pipeline has an issue that prevents it from being used as a tool. Open the pipeline in Builder, check the Issues panel for errors, and resolve them before trying to add the tool again. Click **Inspect** next to any error to jump to the affected component, or click **Fix with AI** to open the AI assistant, which reasons through the fix and can apply it for you.