Milvus MCP: collection not found (check the name and the active database)

TL;DR: The server is connected; the collection name is wrong (or you are in the wrong database). Call milvus_list_collections to see what exists, fix the name, retry.

Collection not found: my_vectors

Fix it

1. List what actually exists:

{ "name": "milvus_list_collections", "arguments": {} }

Expected: a list of collection names. An empty list is normal on a fresh deployment.

1. Check you are in the right database:

{ "name": "milvus_list_databases", "arguments": {} }

Collections live inside databases. If yours is in a non-default database, switch with milvus_use_database.

1. Fix the name in your tool call. Watch for pluralization, prefixes, and case.

Expected: the tool operates on the collection.

When to use this

• The server connects (list-collections works) but a specific collection is reported missing.
• The name was typed by hand or came from another environment.

When NOT to use this

• Connection or permission errors. Fix reachability and auth first.
• The list is empty and should not be. Then the data was never loaded, or you are in the wrong database.

Compatibility

• zilliztech/mcp-server-milvus (milvuslistcollections, milvuslistdatabases, milvususedatabase tools).

Why it happens

Milvus scopes collections to databases, and the default database is default. Data loaded into a named database is invisible until you switch to it, which looks exactly like a missing collection. Add inexact names from agents and this is one of the most common Milvus MCP errors.

Edge cases

• Collection names are case-sensitive.
• Dropped collections stay dropped. Recreate and reload if it was deleted.
• Some tools auto-create collections on first write. Reads never auto-create. A read failing on a fresh setup usually means the write path never ran.