mongo_aggregate

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations exist, and the description does not disclose behavior beyond the generic action. It fails to mention whether the pipeline can include write stages like $merge/$out, authentication requirements, or any side effects. The agent lacks information to understand potential risks.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single, concise sentence with no wasted words. However, it could be improved by including critical details without becoming overly verbose.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the complexity of aggregation pipelines, the lack of an output schema, and absent annotations, the description is incomplete. It omits return format, error behavior, timeout limits, and safe usage patterns, making it insufficient for an agent to fully understand the tool's operation.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The description adds no meaning beyond the input schema's parameter descriptions. Fifty percent of parameters (database and collection) lack descriptions in the schema, and the description does not compensate. The pipeline parameter is described as a JSON string, but no additional context is provided.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool runs an aggregation pipeline on a MongoDB collection, using a specific verb 'Run' and resource 'aggregation pipeline'. This distinguishes it from sibling tools like mongo_find or mongo_count_documents.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides no guidance on when to use this tool versus alternatives such as mongo_find or mongo_distinct. It does not specify prerequisites, limitations, or when not to use an aggregation pipeline.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.