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

Annotations already establish that this is a safe, read-only, idempotent operation. The description adds useful behavioral context beyond the annotations: results are zero-filled, aggregates only, and require a store-connected workspace.

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?

Two compact sentences, with the core purpose front-loaded and the prerequisite placed second. There is no redundant or wasted wording.

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?

The description covers the key domain constraints for calling the tool, especially the store-connected prerequisite and aggregate/zero-filled behavior. With a full input schema and an output schema present, no further explanation of return values is needed.

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%, so the schema already documents all five parameters, including enums and date constraints. The description reinforces the revenue/orders choice and the period concept but does not add meaningful parameter syntax beyond the schema.

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 states a specific resource and measure: daily revenue or order count over a period, with example user intents. It is clearly distinct from most sibling tools, but it does not explicitly contrast itself with nearby analytics tools such as readPerformance or readCustomerStats.

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?

It gives concrete use cases ('revenue trend', 'are sales going up', 'orders per day') and a clear prerequisite: only for workspaces with a connected store, checked via listWorkspaces. It lacks explicit when-not-to-use guidance or named alternatives for adjacent analytics questions.

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