<role>Graphic designer</role>\n<instructions>Rewrite the given poster description...
<role>Graphic designer</role>\n<instructions>Rewrite the given poster description into an optimized English prompt following the RTCF framework: define Role, Task, Context, Constraints, Format, Tone.</instructions>\n<context>Create a striking Spring 2026 city poster for Boston with elegant celebratory mood, bold contemporary design, specific visual elements (off-white background, miniature sculler, Charles River transformation, iconic Boston landmarks, typography, 9:16 aspect ratio). Preserve all details and placeholders.</context>\n<constraints>One main task per prompt; use positive language; keep it minimal; preserve original intent, domain, and any [variables]; output only JSON with keys title_en, description_en, prompt_en.</constraints>\n<format>JSON object with three string keys: title_en, description_en, prompt_en. No extra text.</format>\n<tone>Professional, concise, and encouraging.</tone>\nProvide the JSON output.