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

With no annotations provided, the description carries the full burden of behavioral disclosure. It goes beyond a simple read operation by revealing live unit prices, subtotal calculation, item count, checkoutUrl for human hand-off, a 7-day expiry, and the fact that unavailable lines are flagged and excluded from the subtotal. This is rich, actionable context.

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, dense sentence that front-loads the core purpose ('Read a cart created with update_cart') before enumerating the key response attributes. Every clause earns its place, providing substantial information without unnecessary padding.

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 simple retrieval tool, the description is remarkably complete. It covers what the response contains, the lifetime of the cart, and the handling of unavailable items. The lack of an output schema is compensated by the explicit enumeration of returned fields. No critical behavioral gaps remain.

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 description coverage, and the tool description does not add any information about the parameters (cartId, domain, language). It does not explain required vs optional fields, format expectations, or how domain/language affect the response. The parameter names are self-explanatory but the description fails to provide any additional meaning.

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 clearly states the verb 'Read' and the resource 'cart created with update_cart', distinguishing it from sibling tools like create_order or get_order_status. It also enumerates the specific contents of the response (lines, prices, subtotal, item count, checkoutUrl, expiry), making the tool's purpose unambiguous.

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 specifies that this tool reads a cart that was previously created or updated with the sibling update_cart tool, providing a clear usage context. It does not explicitly mention alternatives or exclusions, but the linkage to update_cart implicitly guides the agent on when to use it.

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