docs: clarify draft bind input behavior

skills/wf-cli/SKILL.md

@@ -57,8 +57,9 @@ wf draft save <workspace_id> --artifact <artifact_id> --version <n> --title <tit
 Draft creation auto-binds required capability inputs only. Optional inputs are
 reported in wrapper-hint notes; bind them explicitly only when the workflow
 should expose them. Use `wf draft bind --from input.x --to local.x` for an
-existing step, or `wf draft add-step --input input.x=x` while adding a step;
-both project the workflow input schema for top-level fields.
+existing step when schema projection may be needed; it is safe if the schema
+field already exists. Use `wf draft set-input --merge --map input.x=x` for a
+pure input-map edit when the workflow schema is already declared.
 
 `wf draft set-workflow-output` projects missing public output schema fields for
 single-field `input.*` and `state.*` sources. Prefer it for final workflow

skills/wf-workflow/references/draft-workspaces.md

@@ -129,6 +129,11 @@ the whole map for that step or output scope. Use repeated `--map` flags in one
 command for a complete replacement. Use `--merge` only when adding/updating
 entries over multiple revisions.
 
+`bind input.x -> local.x` is schema-aware and idempotent when `input.x` is
+already declared. Use it for repair hints or schema projection. Use
+`set-input --merge --map input.x=x` when you only need to update a step input
+map.
+
 - `bind_draft`
 
   Declares a workflow input/state/output schema field from a capability local