posit-dev / posit-dev/mcptools

Support tool _meta in tools/list responses

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Dominant language
R
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196
Forks
21
Avg merge
1h 14m
Merged PRs (30d)
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Description

tool_as_json() emits name/title/description/inputSchema/annotations only; there is no way to attach _meta to a served tool.

MCP Apps requires _meta.ui.resourceUri on the tool that opens the app, and _meta.ui.visibility: [\"app\"] on tools that only the iframe (not the model) may call. ellmer's tool annotations have no slot for arbitrary _meta.

Suggested shape: a meta argument when registering tools (or honoring a _meta field on ellmer tool annotations), passed through verbatim in tools/list.

Part of #115.

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  3. Fork the repository and make your change on a branch.
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Research direction

Start at tool_as_json() and trace the tool-registration path that builds tools/list responses, including how ellmer tool annotations are represented. Determine where the proposed meta argument or annotation field belongs, then verify that tools/list preserves _meta.ui.resourceUri and _meta.ui.visibility verbatim.

Written by the indexing model from the issue text.

Assessment

Tech stack
r
Domain
api, backend
Issue type
Feature
Difficulty
3/5
Estimated time
1-2 days
Activity status
Quiet
Clarity
Mostly clear
Newbie friendliness
68/100

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