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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is well covered. The description adds a usage caution but little additional behavioral context beyond what the annotations provide.

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 a single tight sentence with the positive use case front-loaded and the exclusion immediately after. There is no redundant or wasted 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?

With one parameter, full schema coverage, rich annotations, and an output schema, the description needs only clarify when to use the tool. It does that well, though it could more explicitly distinguish this single-list read from get_lists.

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%, so the single listRef parameter is already documented as an opaque list reference returned by ComingUp. The description adds no parameter-level detail, which is acceptable given the complete 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 indicates the tool is used when existing item details or listItemRef values are needed, implying a read of list contents. It distinguishes itself from appending items, though it does not explicitly say it returns a single household list's details or name the get_lists sibling.

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 a clear use case ('when existing item details or listItemRef values are needed') and an explicit exclusion ('do not call it merely to append items'). It does not name the alternative tool, but the exclusion points clearly away from add_list_items.

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