Prompts - Metadata attributes in prompt registration, similar to resource metadata or tool annotations #703

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1. KKonstantinov

   added

   enhancementRequest for a new feature that's not currently supportedRequest for a new feature that's not currently supported

   on Jun 27, 2025
2. KKonstantinov commented on Jun 27, 2025

   

   KKonstantinov

   on Jun 27, 2025

   Last edited by KKonstantinov

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   A further question on this would be:

   _meta could potentially be used for this, even though it's not part of the prompt definition, but rather the prompt response (e.g. alongside content).

   I'd like some clarity / confirmation if _meta is intended to be used in such a manner.

   ---

   If _meta is the one to use here instead of having something on the prompt definition; quick side comment then is the MCP spec does enforce _meta key name standards which the SDK does not enforce. Could we then add zod validations, as currently the SDK only has _meta: z.optional(z.object({}).passthrough()),

   Key name format: valid _meta key names have two segments: an optional prefix, and a name.

   Prefix:

   If specified, MUST be a series of labels separated by dots (.), followed by a slash (/).
   Labels MUST start with a letter and end with a letter or digit; interior characters can be letters, digits, or hyphens (-).
   Any prefix beginning with zero or more valid labels, followed by modelcontextprotocol or mcp, followed by any valid label, is reserved for MCP use.
   For example: modelcontextprotocol.io/, mcp.dev/, api.modelcontextprotocol.org/, and tools.mcp.com/ are all reserved.
3. felixweinberger

   added

   needs designValid issue but needs maintainer alignment on design or approachValid issue but needs maintainer alignment on design or approach

   P3Nice to haves, rare edge casesNice to haves, rare edge cases

   v2Ideas, requests and plans for v2 of the SDK which will incorporate major changes and fixesIdeas, requests and plans for v2 of the SDK which will incorporate major changes and fixes

   on Dec 16, 2025
4. felixweinberger commented on Dec 16, 2025

   

   felixweinberger

   on Dec 16, 2025

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   @KKonstantinov is this still something you'd like to see for v2?
5. felixweinberger

   added

   needs decisionIssue is actionable, needs maintainer decision on whether to implementIssue is actionable, needs maintainer decision on whether to implement

   and removed

   needs designValid issue but needs maintainer alignment on design or approachValid issue but needs maintainer alignment on design or approach

   on Apr 15, 2026
6. felixweinberger commented on Oct 5, 2026

   

   felixweinberger

   on Oct 5, 2026

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   registerPrompt() accepts _meta since 2.0.0 (#1629). Closing.
7. felixweinberger

   closed this as completedon Oct 5, 2026