Update an item's text and/or completion

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

With no annotations, the description carries full burden and does real work: it discloses that a combined text+status update is executed as two sequential requests that are NOT atomic, which an agent must know to reason about partial-failure states. It also discloses the response shape {id, text, status}. It omits permission/auth requirements and error behavior, keeping it off 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?

Three short sentences, zero filler: purpose first, then valid parameter combinations, then the non-atomicity caveat, then the return shape. The most decision-critical constraint is placed where it cannot be missed and nothing is repeated from the schema.

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 an unannotated mutation tool with no output schema and four undocumented parameters, the description supplies the two things that matter most: the non-atomic update behavior and the return shape. Remaining gaps are authorization requirements and failure semantics for a partially applied update, which an agent would still have to discover.

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 must compensate. It adds real meaning for `text` and `completed` (they can be supplied individually or together, with ordering semantics) but says nothing about `list_id` or `item_id` beyond their presence as required identifiers, and gives no format notes despite the id patterns. Partial compensation justifies the baseline 3.

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+scope: "Update an item's text and/or completion status", which unambiguously separates it from add_item, remove_items, and update_list-style siblings. It names the exact mutable fields rather than restating the title. It stops short of explicitly contrasting with any sibling tool, so it lands just under a 5.

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?

"Pass `text`, `completed`, or both" tells the agent what input combinations are valid, which is useful invocation guidance. However, it never states when to prefer this tool over a delete/re-add pattern or what happens on invalid item_id, and there are no explicit exclusions. Usage is implied rather than prescribed.

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