select_cart_delivery_slot

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

With no annotations provided, the description carries the full burden. It discloses that the tool associates the cart with a slot (a mutation), returns details, and requires an authenticated session. It does not mention failure modes or reversibility, but it covers the key behavior and prerequisites. No contradictions with annotations (none exist).

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 four concise sentences, front-loaded with the primary action. Each sentence adds relevant information: purpose, association action, return details, and authentication requirement. There is no redundant or filler content.

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 simple two-parameter tool, no output schema, and no annotations, the description adequately covers the action, return value (listing the specific fields), and prerequisite. It could optionally add error handling or idempotency notes, but it is complete enough for its complexity.

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 100%, with both parameters (slotRef and storeRef) already fully described. The tool description does not add any extra meaning beyond what the schema provides, so it meets the baseline but does not exceed it.

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 tool selects a delivery or drive time slot for the authenticated user's cart, associates it with a specific store, and returns confirmed slot details. This distinguishes it from siblings like get_delivery_timeslots (which lists slots) and validate_checkout_slot (which likely validates the whole checkout).

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 the tool is used to attach a slot to the cart and mentions the authentication requirement. Though it doesn't explicitly state when not to use it or contrast with alternatives, the prerequisite that the slot reference is 'as returned by the get_delivery_timeslots tool' (in the schema) and the context of siblings give clear guidance. It lacks explicit exclusions but is not misleading.

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