Format an error for a tool result: returns the JSON string
'{"error":"<message>"}'. Return this from a tool's execute (instead of
throwing) when the failure is something the LLM should see and recover
from — e.g. "no results found, try a broader query".
Format an error for a tool result: returns the JSON string
'{"error":"<message>"}'. Return this from a tool'sexecute(instead of throwing) when the failure is something the LLM should see and recover from — e.g. "no results found, try a broader query".