add_items

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

With no annotations, the description carries the full disclosure burden and does well: it states the initial state of new items (unchecked), that listName surfaces in a permission prompt for user confirmation, the duplicate-avoidance constraint, and the return format. What it omits is what happens on partial failure or whether any existing data can be overwritten, which keeps it from a 5.

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 core action and state effect are front-loaded in the first clause, and each subsequent sentence adds a distinct, actionable rule (field formatting, pre-check, branch handling, return format). No filler or repetition.

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?

Three required parameters at full coverage, no output schema — and the description compensates by stating 'Returns the added items in get_items format', which tells the agent what it gets back. The add/ask/replace workflow covers the main ambiguity; only failure and concurrency behavior remain unaddressed.

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% and the nested item fields are already documented in detail, so the schema does the heavy lifting. The description's naming rule ('only the product in name… never the quantity inside the name') is a useful reinforcement of a real failure mode but restates what the schema already says, so baseline 3 applies.

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 and scope: 'Add one or more items to a list in a single call', plus the state effect ('new items start unchecked'). It implicitly separates itself from edit_items via the add-vs-modify workflow, but never names that sibling explicitly, so an agent must infer the boundary.

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 gives explicit preconditions and branching logic: call get_items first to check for an existing item, untick-and-set if checked, ask the user to add-or-replace if unchecked, and never create a duplicate row. This is a complete decision procedure rather than a vague hint, and it names the alternative tool (get_items) to use.

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