Add to cart

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

Discloses mutation (add to cart), idempotency (increases quantity if present), and return value (updated cart with total). No annotations provided, so description carries full burden; it does well.

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 sentences, no wasted words, front-loaded with action. Efficient and clear.

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?

Complete for a simple 2-param tool with no output schema: covers purpose, preconditions, side effects, and return value. Lacks mention of authentication, but sibling login tool suggests 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 coverage is 100%, baseline 3. Description adds little beyond schema: only mentions product_id source and quantity default, which are already in schema descriptions.

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?

Clearly states 'Add a product to the real cart by id', distinguishes from sibling tools like remove_from_cart and set_quantity, and specifies source of id (ametller_search_products).

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?

Explicitly instructs to get product id from ametller_search_products first, and describes behavior if product already present. Lacks explicit when-not-to-use but adequate for context.

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