Set App Starter Prompt

MCP contract for set_starter_prompt.

MCP name: set_starter_prompt

Tool contract

{
  "annotations": {
    "destructiveHint": true,
    "openWorldHint": true,
    "readOnlyHint": false,
    "title": "Set App Starter Prompt"
  },
  "description": "Set or clear an app's authored starter prompt — a short getting-started instruction prefilled in the chat host when a visitor clicks \"Open in Claude\" or \"Open in ChatGPT\" on the app, replacing the generic \"I'm using this Charming app\" body. Use this to frame a shared/remixable app's intended first action for visitors. Write a generic instruction — do NOT embed the app's URL: the app name, description, and URL (and, for unclaimed apps, an access token) are appended automatically at render time, so a hardcoded URL would point every remixer at the template instead of their own copy. Pass `starter_prompt: null` (or an empty string) to clear and revert to the generic default. Owner-only; anonymous apps must be claimed first. Idempotent (re-setting the same value is a no-op). Length cap: 2000 characters.",
  "execution": {
    "taskSupport": "forbidden"
  },
  "inputSchema": {
    "$schema": "https://json-schema.org/draft/2020-12/schema",
    "properties": {
      "app_id": {
        "description": "The app ID (UUID) whose starter prompt should change.",
        "format": "uuid",
        "pattern": "^([0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[1-8][0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}|00000000-0000-0000-0000-000000000000|ffffffff-ffff-ffff-ffff-ffffffffffff)$",
        "type": "string"
      },
      "starter_prompt": {
        "anyOf": [
          {
            "maxLength": 2000,
            "type": "string"
          },
          {
            "type": "null"
          }
        ],
        "description": "Getting-started instruction the chat host receives when a visitor clicks \"Open in Claude\" / \"Open in ChatGPT\". The authored text leads; the app's name, description, URL, and (for unclaimed apps) an access token are appended automatically as context — so write a generic 1–3 sentence instruction (the first action you want the visitor to take, plus any persona/voice), NOT a self-contained prompt and NOT the app's URL. Pass null or \"\" to clear and revert to the generic default. Max 2000 characters."
      }
    },
    "required": [
      "app_id",
      "starter_prompt"
    ],
    "type": "object"
  },
  "name": "set_starter_prompt",
  "outputSchema": {
    "$schema": "https://json-schema.org/draft/2020-12/schema",
    "additionalProperties": false,
    "properties": {
      "message": {
        "description": "Consequence copy the agent should surface to the user. Explains where the prompt is rendered (Open in Claude / Open in ChatGPT) and how to clear it.",
        "type": "string"
      },
      "ok": {
        "const": true,
        "description": "Indicates success. Errors arrive as content with isError:true.",
        "type": "boolean"
      },
      "starter_prompt": {
        "anyOf": [
          {
            "type": "string"
          },
          {
            "type": "null"
          }
        ],
        "description": "The current starter prompt on the app row after this call. Null when the prompt was cleared (or normalized away from whitespace-only input). Otherwise the verbatim authored string."
      }
    },
    "required": [
      "ok",
      "starter_prompt",
      "message"
    ],
    "type": "object"
  }
}