Decrease an item's quantity

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 discloses the key behavior of flooring at 0, which is useful. However, it omits other important behavioral details such as the role of the 'by' parameter, default decrement amount, what happens if 'by' is omitted, and any return values or side effects.

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 that states the core action and a key constraint. Every word earns its place, with no redundancy or filler.

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 absence of annotations and output schema, and with 3 parameters and 0% schema description coverage, the one-sentence description is incomplete. It does not clarify parameter semantics, the default behavior of 'by', return values, or edge cases beyond the floor. More context is needed for an agent to invoke it 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?

The input schema has zero property descriptions, and the description does not compensate. It does not explain that 'by' specifies the decrement amount or what categoryId and itemId refer to. The parameter names are somewhat intuitive, but the description adds no additional meaning 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 uses the specific verb 'Decreases' with the resource 'quantity' and adds a behavioral constraint 'floored at 0 (never negative)', which clearly distinguishes it from sibling tools like increment_item_quantity and set_item_quantity. It precisely states what the tool does.

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 implies usage (when you want to decrease an item's quantity) but does not explicitly state when to use it versus alternatives such as set_item_quantity or increment_item_quantity. No exclusions or alternative guidance are provided, so it relies on the verb's obvious meaning.

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