Stub and Deprecated MCP Tools
This page lists tool names present in the v4.0.10 handler registries that do not perform their advertised operation. Stub tools can return a success-shaped placeholder response, so a successful JSON-RPC exchange is not proof that an administrative or cache operation happened.
The released /mcp/stats, /mcp/query, and conditional /mcp/rag handlers are functional and are documented in their respective references. There is no separate released observation endpoint; operational statistics are served by /mcp/stats.
Partial Configuration Handler (/mcp/config)
get_config, set_config, list_variables, get_status, and constrained Admin-SQL query have released implementations. Only this advertised tool is a stub:
| Tool | Released behavior |
|---|---|
reload_config | Returns success with Configuration reload functionality to be implemented; it does not load disk or memory configuration into runtime. Use the documented LOAD MCP VARIABLES ... Admin commands instead. |
Administrative Handler (/mcp/admin)
The endpoint is registered when its handler initializes, but every advertised tool returns placeholder data without performing the operation:
| Tool | Placeholder arguments/result |
|---|---|
admin_list_users | Empty users array. |
admin_show_processes | Empty processes array. |
admin_kill_query | Echoes process_id; does not kill a query. |
admin_flush_cache | Echoes cache_type (query_cache, host_cache, or all); does not flush. |
admin_reload | Echoes target (users, servers, or all); does not reload. |
Cache Handler (/mcp/cache)
The endpoint is registered when its handler initializes, but all six tools are stubs:
| Tool | Placeholder arguments/result |
|---|---|
get_cache_stats | Returns zero entries, hit rate, and memory usage. |
invalidate_cache | Echoes pattern; does not invalidate entries. |
set_cache_ttl | Echoes ttl_ms; does not change TTL. |
clear_cache | Returns an implementation-pending message; does not clear the cache. |
warm_cache | Reports the supplied query count; does not execute the queries. |
get_cache_entries | Returns an empty entries array and the requested limit. |
Deprecated AI Handler (/mcp/ai)
/mcp/ai is registered only when AI_Features_Manager and its handler initialize. Its registry advertises ai_nl2sql_convert, but every call returns a deprecation error directing users to generic LLM queries through the MySQL protocol. It is not a functional NL2SQL tool.
These registries may change in later releases. Always use tools/list against the running version and confirm the corresponding handler documentation before relying on an effectful tool.