The schema version labels the tool arguments

The version is part of the call

A tool’s arguments are names and values. Those names are defined by a schema. If the trace records a schema version, that version is the dictionary for this call. A later edit can reuse a name for a different meaning. Reading yesterday’s call with today’s schema can swap what the value was.

If the trace has no schema version, write “schema version not recorded.” Do not attach the version you deployed this morning.

A renamed field is not the same field

When version 2 renames room to room_id, a version 1 trace that says room is not missing room_id. It used the old name. Quote the name that is on the trace, and say which version. Do not fill room_id with the old room value and call it the version 2 field unless a written migration says they are the same and you cite that note.

What to file

File the tool name, the schema version, and the argument names that appear, with values only when they are safe to copy. If a value may be a secret or a customer record, write the name and “withheld.” File the decision and the tool status on their own lines, as the trace already separates them.

Worked case: room read with the new schema

A trace from yesterday says schema version 1 and argument room set to “B”. Today’s schema version 2 uses room_id for the identifier and room for a display label. A draft files room_id B and says the identifier was B. The version 1 field room was the display label in that schema’s note, which the team wrote down when they shipped version 1.

The note quotes version 1 and room “B” as the display label under that version. It does not copy the value into room_id. The identifier for that call is “not this field.” Today’s schema is not applied backwards.

tool: book_room
schema version on the trace: 1
argument present: room = B
version 1 note: room is the display label
version 2 field room_id: not on this trace
write: label B under version 1
not: room_id B