Default and Optional Parameters in Tool Input Schema Causing Validation Issues Still
Tools
There seems to be a reoccurrence of the linked thread below. I posted in that thread if we want to continue conversation there.
help-bugs-problemsDefault and Optional Parameters in the input schema is causing tool validation issues
In short, we’ve had to add our own temporary patch at the moment:
The patch works around a mismatch between 'zod-from-json-schema' (which marks non-required fields as '•optional() but NOT '
•nullable ()') and LLM
tool-call output (which commonly sends 'null' or 'undefined' for omitted optional fields). Without these patches, Mastra's 'validateToolInput' rejects the first parse attempt and falls back to 'stripNullishValues' - which silently drops fields.
help-bugs-problemsDefault and Optional Parameters in the input schema is causing tool validation issues
In short, we’ve had to add our own temporary patch at the moment:
The patch works around a mismatch between 'zod-from-json-schema' (which marks non-required fields as '•optional() but NOT '
•nullable ()') and LLM
tool-call output (which commonly sends 'null' or 'undefined' for omitted optional fields). Without these patches, Mastra's 'validateToolInput' rejects the first parse attempt and falls back to 'stripNullishValues' - which silently drops fields.
