purchases_quantity

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

No annotations are provided, so the description carries the full behavioral burden. It says this is a read-style 'Get' operation, but does not disclose authentication requirements despite the apiKey parameter, rate limits, return format, granularity behavior, or how missing optional parameters are handled. The description adds very little beyond the tool name.

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 front-loaded sentence with no filler. Structurally it is efficient, though its brevity contributes to under-specification rather than conciseness through precision.

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 7-parameter analytics tool with two required fields, no annotations, no output schema, and only 57% schema description coverage, this description is too sparse. An agent lacks enough context about required inputs, time-range semantics, and expected return shape to call the tool confidently.

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 57%, meaning several parameters are not documented by the schema itself. The description adds no parameter meaning at all: it does not explain product_id, length, ending_at, app_id, unit, apiKey, or restEndpoint. It also does not resolve the discrepancy between length being described as 'Number of days' and unit allowing hour/week/month.

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 verb and resource: 'Get purchase quantity analytics over time.' It is clear enough that this retrieves quantity analytics and not product or revenue analytics. However, it does not explicitly name or distinguish the sibling tools purchases_products or purchases_revenue, so sibling differentiation is only implied.

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 gives no guidance on when to use this tool versus alternatives such as purchases_products or purchases_revenue. It also omits prerequisites, time-range expectations, or when the required product_id and length parameters should be supplied. Usage is only vaguely implied by 'over time.'

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