Loading ToolBench
MCP server to interact with the mongodb database and perform basic operations. The module has some specifications, based on the business rule we are working on, to manage product catalogs.
MongoDB MCP has 13 tools with complete input schemas and basic descriptions. Naming follows verb_noun convention (createIndex, dropIndex, find, etc.). However, descriptions are generic and lack LLM-optimized guidance on WHEN to use each tool vs. alternatives. Parameter descriptions exist but are minimal (avg ~40 chars vs. baseline 72). No output schemas documented. Error handling is basic (McpError thrown but no recovery guidance). Missing tool annotations (readOnlyHint, destructiveHint) despite clear risk classifications. No pagination support on list/find operations despite potential for large result sets.
Executes an aggregation pipeline on a collection. Useful for complex queries, data transformations, and analytics.
Analyzes the schema of a collection by sampling documents and inferring their structure.
Executes multiple write operations (insert, update, delete) in a single batch on a collection.
Creates a new collection in the database.
Create a new index on a collection
Delete a single document from a collection
Drops (deletes) a collection from the database.
No output schemas documented. LLMs cannot infer what fields to expect from tool responses, forcing them to guess at downstream field names and risk broken tool chains.
Missing tool annotations (readOnlyHint, destructiveHint, idempotentHint). Risk classifications exist in metadata but are not exposed via MCP tool schema, preventing clients from warning users before destructive operations.
No pagination support on list/find operations. 'find' tool has limit (max 1000) but no offset/cursor or total count. Large collections risk context window exhaustion.
| Scored | Grade | Overall | Spec posture | Rubric |
|---|---|---|---|---|
| 2026-09-23 | D | 53 | 2026-07-28+ | v2 |
Drop an index from a collection
Query documents in a collection using MongoDB query syntax
List indexes for a collection
Insert a single document into a collection
List all available collections in the database
Update a single document in a collection
Descriptions lack LLM-optimized guidance. Generic descriptions like 'Query documents in a collection' do not explain WHEN to use find vs. aggregate, or what the LLM should expect in return.
Error handling provides no recovery guidance. McpError is thrown but messages do not suggest next steps (e.g., 'Collection not found. Try listCollections() to see available collections.').