--- title: "MongoDB schema design: review, setup & limitations · Undominated.ai" canonical: https://undominated.ai/skills/mongodb-schema-design/ description: "Pins MongoDB's schema-design skill, which separates read checks from writes and says write tools need an explicit yes." --- # MongoDB schema design: review, setup & limitations · Undominated.ai > Pins MongoDB's schema-design skill, which separates read checks from writes and says write tools need an explicit yes. [← Explore all skills](/skills/) DATABASES / MongoDB # MongoDB schema design Pins MongoDB's schema-design skill, which separates read checks from writes and says write tools need an explicit yes. [See setup guidance ↓](#setup)[Original source ↗](https://github.com/mongodb/agent-skills/tree/c370a63b27075008a92134686b24af3817edeb00/skills/mongodb-schema-design) SOURCE REVIEW Reviewed 2026-10-15 Evidence 4 linked sources Publisher MongoDB Licence [Apache-2.0 ↗](https://github.com/mongodb/agent-skills/blob/c370a63b27075008a92134686b24af3817edeb00/LICENSE) Revision c370a63b2707 [Read what was—and wasn’t—checked ↓](#review) “MongoDB schema design patterns and anti-patterns. Use when designing data models, reviewing schemas, migrating from SQL, or troubleshooting performance issues caused by schema problems. Triggers on "design schema", "embed vs reference", "MongoDB data model", "schema review", "unbounded arrays", "one-to-many", "tree structure", "16MB limit", "schema validation", "JSON Schema", "time series", "schema migration", "polymorphic", "TTL", "data lifecycle", "archive", "index explosion", "unnecessary indexes", "approximation pattern", "document versioning".” [MongoDB · upstream description ↗](https://github.com/mongodb/agent-skills/blob/c370a63b27075008a92134686b24af3817edeb00/skills/mongodb-schema-design/SKILL.md) Our analysis follows below. 01 / THE REASONING ## Why this made the selection. - The catalogue has MongoDB's query-optimizer skill and not this schema-design skill. - The file names which MCP tools it may run on its own and which it says need a yes, including drop-database. ### A good fit for - Reviewing an embed-versus-reference choice before any collection change is proposed ### Weigh up before choosing - This review did not execute the resource. - The MongoDB MCP server was not connected, so the skill's automatic schema and size checks were not run. - Rule counts in the skill, such as 11 design patterns, were not re-counted from a separate rules directory. - The source describes query statistics as read-operation evidence, so write patterns need another diagnostic source. 02 / THE REVIEW RECORD ## What we actually inspected. Source review has boundaries. A clear record is more useful than a “safe” badge. ### Material inspected - skills/mongodb-schema-design/SKILL.md - README.md - LICENSE ### Our findings - The skill says data that is accessed together should be stored together, and it points schema checks at a MongoDB MCP server when one is connected. - It says to use --readOnly for safety and to remove that flag only when writes are needed. - Its action table marks find, aggregate, collection-schema, db-stats, and count as runnable without a prompt, and marks update-many, insert-many, create-collection, delete-many, drop-collection, and drop-database as requiring explicit confirmation. ### Not established by this review - The resource was not executed and its tools were not called. - No MongoDB command was sent. - The MCP server named in the skill was not started. - Not executed: it was not installed or run. The review applies to the material and revision named here. A newer upstream release can change its behavior. 03 / PUT IT TO WORK ## Add a skill to your workflow. [Upstream setup instructions ↗](https://github.com/mongodb/agent-skills/blob/c370a63b27075008a92134686b24af3817edeb00/README.md) DOCUMENTED COMMAND npx skills add mongodb/agent-skills Copy command ↗ Run in your terminal to choose your AI tools, project or global scope, and installation method. This short command follows the current upstream version; the review covers the revision shown above. - The README's direct skills install is the command above and does not configure an MCP server. - The same README says /plugin install mongodb-atlas configures the hosted Atlas MCP server over OAuth. - For a self-managed deployment it points at a different mongodb plugin and README.community.md, which this review did not open. ### Before you start - A skills-compatible agent - Optional MongoDB MCP server if the skill's live checks are used - A database the operator is allowed to inspect ### Compatibility Claude · Cursor · OpenAI Codex · GitHub Copilot · Grok ### Skill text, with writes gated by the skill's own confirmation rule - Read the skill - Run the listed read-only MCP tools only if a MongoDB MCP server is connected - Run the listed write tools only after the confirmation the skill requires ### Cost model Apache-2.0; no database connection was opened 04 / FOLLOW THE EVIDENCE ## The source trail. Our notes are separate from the original resource. Check upstream before adopting a new version. - [mongodb-schema-design SKILL.md ↗](https://github.com/mongodb/agent-skills/blob/c370a63b27075008a92134686b24af3817edeb00/skills/mongodb-schema-design/SKILL.md) Checked 2026-10-14 https://github.com/mongodb/agent-skills/blob/c370a63b27075008a92134686b24af3817edeb00/skills/mongodb-schema-design/SKILL.md Supports: embed principle and write-confirmation table - [Repository README ↗](https://github.com/mongodb/agent-skills/blob/c370a63b27075008a92134686b24af3817edeb00/README.md) Checked 2026-10-14 https://github.com/mongodb/agent-skills/blob/c370a63b27075008a92134686b24af3817edeb00/README.md Supports: skills install line and Atlas plugin distinction - [Repository LICENSE ↗](https://github.com/mongodb/agent-skills/blob/c370a63b27075008a92134686b24af3817edeb00/LICENSE) Checked 2026-10-14 https://github.com/mongodb/agent-skills/blob/c370a63b27075008a92134686b24af3817edeb00/LICENSE Supports: Apache License Version 2.0 - [Pinned source review C2-W10 ↗](https://raw.githubusercontent.com/mongodb/agent-skills/c370a63b27075008a92134686b24af3817edeb00/skills/mongodb-schema-design/SKILL.md) Checked 2026-10-15 https://raw.githubusercontent.com/mongodb/agent-skills/c370a63b27075008a92134686b24af3817edeb00/skills/mongodb-schema-design/SKILL.md Supports: upstreamDescription, limitations, review.notTested, review.reviewedAt KEEP COMPARING ## Other approaches to consider. Related by category or shared topics. These are alternatives to inspect, not a measured quality order. [### MongoDB query optimizer ↗ Official MongoDB skill that limits itself to slow-query and index work and names the MCP tools it expects for explain, indexes, and Atlas Performance Advisor.](/skills/mongodb-query-optimizer/)[### MongoDB Search and AI ↗ Chooses between Atlas Search, Vector Search, Automated Embedding and hybrid search, and creates indexes only after explicit approval.](/skills/mongodb-mongodb-search-and-ai/)[### Azure Cosmos DB for Python ↗ Use Cosmos DB NoSQL clients for partition-aware document operations and parameterized queries.](/skills/microsoft-azure-cosmos-py/) [AI Tools ↗](/tools/)[Skills ↗](/skills/)[Agents ↗](/agents/)[MCP Servers ↗](/mcp-servers/)[Workflows ↗](/workflows/) ## Continue your investigation - [Choose a toolkit](/tools/) - [Inspect execution hosts](/agents/) - [Check tool access](/mcp-servers/) - [Check project dependencies](/check-repo/)