AI Agent : Runtime Error 400

:bullseye: What is your goal?

Run an HR agent, leveraging a knowledge file (PDF-formatted CV), and a Notion MCP (enabling access to my job search history).
Thanks for your help

:thinking: What is the problem & what have you tried?

Encoutering a runtime error 400 each time I try to run my scenario.
I tried simplifying my scenario to the max (leaving just one Agent Knowledge), and one MCP (Notion), but it does not change anything.

:clipboard: Error messages or input/output bundles

400 | Your request cannot be processed due to a validation error.| {“code”:“too_big”,“maximum”:4000,“type”:“string”,“inclusive”:true,“exact”:false,“message”:“String must contain at most 4000 character(s)”,“path”:[“tools”,3,“description”]}

:camera_with_flash: Screenshots (scenario flow, module settings, errors)