Utility Tools

These tools are implemented inside the Discord MCP itself. They do not map one-to-one to a Discord REST route, but they solve common integration problems that would otherwise require extra application code.

util_custom_data #

Use this tool to store or retrieve a small JSON object tied to the current app.

• id is required and can be:
• public
• private
• a guild snowflake
• content is optional:
• omitted or null -> read
• "", "{}", or {} -> delete
• JSON object or serialized JSON object string -> write

Access rules:

• public: readable by anyone, writable only with X-Owner-Access
• private: always requires X-Owner-Access
• guild snowflake: allowed only when the guild is within X-Target-Guilds

Values expire automatically after 7 days, and every successful read or write refreshes that timer.

util_generate_image #

Use this tool to generate one image through the configured provider and get a usable URL back.

Input:

• prompt
• size (optional, format WxH when supported by the selected provider)

Output:

• url
• provider
• model
• source
• content_type when the Discord MCP had to inspect or upload the file content

This tool is only visible when the current application has a usable image provider configuration.

If an uploader is configured, the Discord MCP may reupload the generated result before returning the final URL.

In tools/list, the Discord MCP also adapts this tool's metadata to the currently selected provider. When the provider supports request-time size overrides, the size field is shown with provider-specific guidance.

For provider-specific configuration, selection rules, and required fields, see Providers.