add_to_cart

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

Annotations already declare readOnlyHint=false, destructiveHint=false and openWorldHint=true; the description's 'Nothing is ordered yet' usefully reinforces that the mutation is non-committal and it discloses the return payload. It does not cover availability/stock failures, quantity merge behavior, or addon/topping validation.

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 short sentences, front-loaded with the action and then the key constraint. No 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?

An output schema exists, so return values need no prose. However, with 0% schema coverage the description should compensate for the undocumented quantity/addon/topping parameters, and it does not.

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 0% and four parameters exist, yet the description mentions only 'a product' (product_id). Quantity, addon_ids, and topping_ids receive no semantic explanation anywhere, leaving the agent to guess their meaning and accepted values.

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?

States a specific verb and resource ('add a product to the cart') plus the side effect on return ('return the updated cart'). 'Nothing is ordered yet' separates it from place_order, though no sibling is named explicitly.

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?

Usage is implied: 'Nothing is ordered yet' nudges the agent to use this before place_order, but there is no explicit when/when-not guidance or reference to update_cart_item for adjusting quantities.

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