Heads-up issue: server-everything (modelcontextprotocol/servers)

Repo: https://github.com/modelcontextprotocol/servers
Filed by: PengSpirit
Filed before: Apr 25, 2026 (72h before Apr 29 launch of mcp-probe)

Title

get-resource-reference prompt: resourceType arg is missing a description, blocks automated invocation

Body

Hi — running mcp-probe against @modelcontextprotocol/server-everything@2026.1.26 surfaces one schema warning that becomes a hard failure when the prompt is invoked:

WARN  get-resource-reference — Property "resourceType" missing description
FAIL  resource-prompt — MCP error -32603: Invalid resourceType: test. Must be Text or Blob.

The server correctly enforces the enum, but because MCP prompt arguments don't carry a JSON schema (only name / description / required), there's no machine-readable way for a caller to know that resourceType accepts only Text or Blob. The convention is to encode allowed values in the description (e.g. "Type of resource. Must be Text or Blob."). Without that, every automated caller has to guess.

Suggested fix: populate the description field on the resourceType argument of the get-resource-reference prompt with prose that names the allowed values, e.g. "Type of resource — must be 'Text' or 'Blob'."

mcp-probe already has a fallback heuristic that extracts allowed values from descriptions matching "must be X or Y" / "one of: X" (commit 3825170 in the mcp-probe repo). Once the description is filled in, this prompt would pass cleanly.

This is a schema-completeness issue, not a server bug — the server itself works correctly. Filing a friendly heads-up because we're about to publish a scorecard that includes this finding, and want maintainers to have time to respond.

Repro:

npx -y @incultnitostudiosllc/mcp-probe test "npx -y @modelcontextprotocol/server-everything"

Thanks for server-everything — it's the most useful integration test target in the ecosystem precisely because it exercises every protocol corner.