The 3ngram MCP server exposes the following introspection tools.
Every entry is generated from the tool’s source signature and docstring,
so this page never drifts from the backend.
Required parameters are marked with the required attribute. Optional
parameters show their default value.
get_index_stats
Get Index Stats · read-only · non-destructive · idempotent · closed-world
Return counts for memories, content chunks, and sources in one call.
Call this before searching when you need to decide whether a search is
even worth running for the current user. content_chunks == 0 means
nothing is indexed yet; memory_count == 0 means no accountability
state exists. Either result is a strong signal to stop guessing and tell
the user what’s missing.
Returns a dict shaped as :class:IndexStats:
{memory_count, content_chunks, sources_count, last_index_update, embedding_model}.
Returns: dict[str, Any]
Source: backend/src/engram/mcp/tools/introspection.py
This tool takes no parameters.
list_sources
List Indexed Sources · read-only · non-destructive · idempotent · closed-world
List connected content sources (GitHub repos) with indexing status.
Shows each repo’s sync status, last indexed time, and any errors.
Returns: str
Source: backend/src/engram/mcp/tools/content_sources.py
This tool takes no parameters. 
