my mcp server get error "MCP error -32602: Tool findDocument not found"

[clsljt]

I'm using python clinet and nodejs server with ubuntu. When running the server always have the error "MCP error -32602: Tool XXX not found"

MongoDB Lens v9.1.0 starting…
MongoDB Lens server running.
\n连接到服务器，工具列表: ['connect-mongodb', 'connect-original', 'add-connection-alias', 'list-connections', 'list-databases', 'current-database', 'create-database', 'use-database', 'drop-database', 'create-user', 'drop-user', 'list-collections', 'create-collection', 'drop-collection', 'rename-collection', 'validate-collection', 'distinct-values', 'find-documents', 'count-documents', 'insert-document', 'update-document', 'delete-document', 'aggregate-data', 'create-index', 'drop-index', 'get-stats', 'analyze-schema', 'generate-schema-validator', 'compare-schemas', 'explain-query', 'analyze-query-patterns', 'bulk-operations', 'create-timeseries', 'collation-query', 'text-search', 'geo-query', 'transaction', 'watch-changes', 'gridfs-operation', 'clear-cache', 'shard-status', 'export-data']
\nMCP Client 启动!
输入您的查询或 'quit' 退出.
\nQuery: List of all accessible databases
准备调用工具: listDatabases
参数: {}
\n错误: MCP error -32602: Tool listDatabases not found
\nQuery: List of all accessible MongoDB databases
准备调用工具: listDatabases
参数: {}
\n错误: MCP error -32602: Tool listDatabases not found
\nQuery: databases
准备调用工具: databases
参数: {}
\n错误: MCP error -32602: Tool databases not found
\nQuery: testDB里面有多少数据
准备调用工具: shard-status
参数: {
  "collection": "testDB",
  "target": "database"
}
Error getting shard status for database 'testDB': no such command: 'listShards'
\n[Calling tool shard-status with args {'collection': 'testDB', 'target': 'database'}]\n
\nQuery:  testDB中bob多大               
\n您的问题似乎缺少了一些具体的上下文，特别是关于“中bob”是什么意思。您能提供更多的信息或背景吗？例如，“中bob”是指一个角色、一个名字还是其他什么内容呢？这样我就能更好地帮助您了。
\nQuery: testDB中名字是Bob的年纪多大
准备调用工具: findDocument
参数: {
  "collection": "people",
  "database": "testDB",
  "filter": {
    "name": "Bob"
  },
  "projection": {
    "_id": 0,
    "age": 1
  }
}
\n错误: MCP error -32602: Tool findDocument not found
\nQuery:



If there have some way to solve this.

[furey]

Hi @clsljt

Thanks for trying MongoDB Lens

I'm not familiar with your Python client (can you provide more details please), but it looks like your client interpreter logic isn't returning correct tool names (its returning camelCase for tool names, but MongoDB Lens tool names are kebab-case)

- listDatabases (incorrect)

should be

+ list-databases (correct)

Referring to the MongoDB Lens docs, a user query is usually interpreted by an LLM to select the correct tool to run against it, and it looks like your client is returning invalid tool names for whatever reason

Cheers

[clsljt]

Thanks for you reply, after conducted some tests，I think the reason can't use the correct tool names is caused by LLM. I use the Qwen2.5-32b on the Ollama. This model will return all kinds of tool names, such as list_databases, listDatabases. After multiple attempts, i can read my databases by this server.

So i think the reason caused this error is LLM, the server is ok.

Thanks again

[furey]

@clsljt Nice one—cheers 🚀