Tool parameters use camelCase JSON names, breaking MCP clients that send snake_case

[drorh-st]

Problem

When MCP clients (e.g. Claude Code) call tools like query_prometheus or list_loki_label_names, the parameters are silently ignored because the tool schemas define camelCase JSON field names (e.g. datasourceUid, startTime, queryType) while many MCP clients normalize parameter names to snake_case before sending them.

The result is that datasourceUid arrives as datasource_uid, doesn't match, defaults to empty string, and the server calls GET /api/datasources/uid/ with no UID — returning a 400 "id is invalid" error.

Steps to reproduce

Call query_prometheus with datasource_uid (snake_case) — the query fails with:

getting Prometheus client: get datasource by uid : [GET /datasources/uid/{uid}][400] getDataSourceByUidBadRequest {"message":"id is invalid"}

Calling the same tool manually with datasourceUid (camelCase) works correctly.

Environment

• mcp-grafana: v0.11.2
• Grafana: 12.3.3
• MCP client: Claude Code 2.1.72

Expected behavior

Tool parameter names should use snake_case (e.g. datasource_uid, start_time, query_type) to be compatible with standard MCP client behavior, or the server should accept both naming conventions.