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

Annotations already establish read-only, idempotent, non-destructive behavior, and the description adds meaningful context: all item problems are returned at once with per-item pricing, fulfillment parameters trigger additional time/address/minimum-order checks, and nothing is saved. It could say more about the returned problem structure, but it adds solid value beyond annotations.

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 front-loaded with the core validation purpose and uses one dense but efficient sentence. It packs a lot of useful information without obvious repetition, though it is somewhat compressed.

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 complex tool with six parameters, nested option objects, and no output schema, the description covers the main validation dimensions and explicitly states non-persistence. It omits the 'shop' parameter context and the exact shape of validation responses, but remains largely complete.

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 67%, and the description explains the conditional roles of fulfillment, date, time, and address. However, it does not mention the 'shop' parameter's context or add much detail about the nested option structures beyond what the schema already provides; baseline 3 is appropriate.

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 a specific verb and resource ('Check a cart') and clearly frames the tool as pre-quote validation that 'saves nothing', which separates it from quote_order/place_order. It does not explicitly distinguish itself from related check_stock/check_delivery tools, keeping it just shy of a 5.

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?

It implies the use case ('before quoting') but gives no explicit when-not guidance and does not name alternatives such as check_stock, check_delivery, quote_order, or get_checkout_requirements. The workflow context is useful but incomplete.

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