update_item

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It only says 'update,' which implies mutation, but omits critical details such as whether it performs a partial or full replacement, error handling for non-existent items, permission requirements, or return values. This is a significant gap for a mutation tool.

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, direct sentence with no filler words. It is front-loaded with the action verb and resource, making it easy to scan. It earns its place despite being minimal.

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 nested object parameter, three required fields, and no output schema, the one-line description is insufficient. It fails to explain update semantics (partial vs. replace), response format, or error conditions. With no annotations to fill gaps, the tool is under-specified for an agent to fully anticipate behavior.

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 has 100% description coverage for all three parameters, providing basic semantics (e.g., item_id is the ID, item_data is the data to update). The tool description adds no further meaning about parameter usage, such as how item_data is structured or whether it is a partial update. Since the schema already covers baseline semantics, the description neither helps nor harms.

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 'Update an existing item in Business Central' clearly states the action (update) and the target (item), and the mention of 'existing' distinguishes it from create_item. However, it is somewhat generic, lacking specificity about what 'item' refers to beyond the schema's resource parameter, which slightly reduces clarity.

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?

No guidance is provided on when to use this tool versus alternatives like create_item or delete_item. The description does not mention prerequisites, such as the item needing to exist, or suggest checking get_schema for valid fields. This leaves the agent without clear context for selection.

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