ht_add_to_shopping_list

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

Annotations already declare readOnlyHint=false, destructiveHint=false, and openWorldHint=true, so the safety profile is covered. The description adds genuinely new behavioral information the annotations cannot convey: the operation is additive and merges into an existing quantity rather than overwriting it. It does not mention per-call item caps or failure behavior for invalid UPCs.

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 tight sentences, no filler. The additive-quantity caveat sits in parentheses right where the action is described, and the undo pointer is front-loaded at the end rather than buried.

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 two-required-parameter mutation with no output schema, the description covers what the tool does, how quantities behave, and how to reverse it. Minor residual gaps are whether the target list must already exist and whether partial failures are possible on multi-item calls.

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 50%: listId and upc carry their own descriptions, while quantity has only constraints and a default. The description compensates partially by explaining that quantity accumulates onto any existing entry, which is the semantic an agent most needs, but it says nothing about the 50-item batch limit or quantity bounds.

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 states a specific verb and resource ('Add items to a Harris Teeter shopping list') plus the keying dimension ('by UPC'), which cleanly separates it from cart-oriented siblings like ht_add_to_cart. An agent can identify the operation without opening the schema.

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 names the reversal path explicitly ('Undo with ht_remove_from_shopping_list'), giving an agent a clear recovery alternative. There is no explicit 'use this instead of X when...' routing against ht_add_to_cart or ht_create_shopping_list, so it falls short of full when/when-not guidance.

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