[Bug] Workflow tool delivers JSON args as string instead of parsed object

Bug Description
Title: Workflow tool — object/array passed as args arrives in the script as a JSON string, contradicting the documented "verbatim" contract

Summary: When the Workflow tool is invoked with args set to a JSON object or array, the workflow script's args global is a JSON-encoded string, not the parsed value. The tool description says args is delivered "verbatim" and that passing "arrays/objects as actual JSON values" lets the script call args.map/args.filter — but those fail because args is a string, so args.foo is undefined and args.map throws.

Minimal repro (zero agents): Workflow call with args: {"probe":"hello","n":42} and script:
export const meta = { name: 'args-diag', description: 'x' }
return { argsType: typeof args, probe: (args && typeof args === 'object') ? args.probe : '(not object)' }

• Observed: {"argsType":"string","probe":"(not object)"} — args is the literal string "{\"probe\":\"hello\",\"n\":42}".
• Expected (per docs): argsType: "object", args.probe === "hello".

Impact: Scripts written to the documented pattern silently get undefined. In my case, a fan-out workflow interpolated undefined file paths into subagent prompts (${args.contextPath} → "undefined"), degrading context-passing — the agents recovered, but it's a silent footgun.

Workaround: const a = typeof args === 'string' ? JSON.parse(args) : args;

Suggested fix: Either deliver args already-parsed (match the docs), or correct the tool description to state args arrives as a JSON string requiring JSON.parse.

Env: Claude Code · model claude-opus-4-8[1m].

Environment Info

• Platform: darwin
• Terminal: WezTerm
• Version: 2.1.195
• Feedback ID: 3a21a48d-ae1c-44cd-990d-33f4b6e41cff

Errors

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