update_item

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It only states 'modify,' which implies a write operation, but it does not disclose whether the tool is idempotent, whether it performs a partial update or full replacement, what kind of permissions are required, or any error conditions. This lack of transparency is a significant gap.

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 sentence that immediately conveys the tool's purpose. It is appropriately short and front-loaded, with no unnecessary words or redundancy.

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?

Given the tool has a single required parameter with a nested object and an output schema (not shown), the description should at least hint at the return behavior or side effects. It does not mention that the update is likely partial (only specified fields are modified) or that it requires an existing item. The sibling list includes many related operations, and the description lacks enough context for an agent to understand the tool's role in a workflow.

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?

The input schema defines parameters item_key (string) and fields (object with additional properties), but the description does not explain their meaning or usage. With 0% schema description coverage, the description should compensate by clarifying what item_key represents (e.g., unique identifier) and that fields contains the fields to update. It fails to do so, leaving the parameter semantics entirely to the 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 clearly states the verb 'modify' and the resource 'existing item', which distinguishes it from sibling tools like add_item (create) and delete_item (delete). However, it could be more specific by mentioning the parameters (item_key and fields) to further differentiate from potential update tools for other resources.

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 no information about when to use this tool versus alternatives (e.g., add_item, delete_item, or update_collection). There is no mention of prerequisites, context, or prohibitions, leaving the agent without guidance on selecting this tool appropriately.

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