aggregate_eta_data

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

With no annotations, the description carries the full burden of behavioral disclosure. It states 'read-only', which is a useful safety trait, but does not elaborate on potential side effects (e.g., whether $out/$merge stages are blocked), execution limits, or authorization requirements. The read-only claim may also be misleading if the pipeline allows write stages.

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 sentence, front-loaded with the action and resource. It is concise with no wasted words, making it easy to parse quickly.

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?

For a tool with only two parameters and no output schema, the description is adequate but not rich. It omits return behavior, error conditions, and any restrictions on pipeline stages. The presence of sibling tools for listing collections partially compensates for missing context.

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?

Schema description coverage is 100%, with clear descriptions for both 'collection' and 'pipeline'. The description adds no extra meaning beyond the schema, meeting the baseline for schema-heavy tools.

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 uses a specific verb ('Execute'), a clear resource ('MongoDB aggregation pipeline on eta data'), and a key qualifier ('read-only'). This clearly distinguishes it from sibling tools like query_eta_data or count_eta_documents, which serve different purposes.

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 query_eta_data, count_eta_documents, or get_eta_collection_stats. It does not mention scenarios where aggregation is preferred or any exclusions.

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