add_item

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

With no annotations, the description carries the full burden of behavioral disclosure. It explicitly states that the tool either adds an item or updates the note on an existing one, making the mutating nature clear. It does not detail edge cases like whether the note is replaced or merged, but the core side effect is transparently described.

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 compact and front-loaded: a one-sentence purpose followed by a concise, well-formatted Args block. Every sentence adds value, and there is no redundant or filler text.

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 three-parameter tool with an existing output schema, the description covers everything needed to invoke it correctly: the operation, the add/update nuance, and all parameter semantics including the default list behavior. No critical information is missing.

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 0%, so the description fully compensates. It explains each parameter with concrete examples ('Milk', '2 litres'), clarifies specification is an optional note, and defines the list parameter as 'List name or uuid. Omit to use the BRING_LIST default.' This adds significant meaning beyond the bare schema.

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 opens with a specific verb+resource statement: 'Add an item to a shopping list, or update the note on an existing one.' This clearly distinguishes the tool from its siblings (remove_item, complete_item, get_lists, get_list_items) by naming the exact operation and the add-vs-update behavioral split.

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 provides clear context: use this tool to add an item or update an existing item's note. It does not explicitly exclude or route to sibling tools like remove_item or complete_item, but the purpose is so specific that an agent can reliably infer when this tool applies.

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