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

Annotations already declare destructiveHint=false and idempotentHint=false, so the safety profile is covered. The description adds non-obvious behavior the annotations cannot convey: additions are visible to all household members, are labelled 'via AI', and re-calling duplicates items. It does not describe failure or ambiguity handling, so it is strong but not exhaustive.

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?

Three tight sentences with zero filler. The core action is front-loaded, followed by parameter choice and then behavioral caveats in descending order of importance.

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?

There is no output schema, so the description carries the return-value burden, and it does not say what a successful call returns or how ambiguous natural-language text is resolved. For a two-parameter add tool whose annotations cover the safety profile, this is a minor gap rather than a blocking one.

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%, so the baseline is 3, but the description adds real meaning: `text` accepts natural language in any language (with a worked example), and `items`, when given, is used instead of `text` — an implicit precedence rule the schema's 'used instead of text when given' only hints at structurally.

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?

States a specific verb ('Add') and resource ('products to the household's shared FeedMyCart shopping list') with scope ('one or more'). It is immediately distinguishable from the read-side siblings read_list, read_pantry, and search_deals.

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?

Gives clear context for choosing between the two input modes: use `text` for natural language in any language, or `items` for a structured list. It does not name explicit exclusions or point at a sibling for related tasks (e.g., reading or checking the list), so it stops 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.