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

Annotations already flag destructiveHint=true and non-idempotent, so the bar is lower; the description still adds real value by explaining that the underlying PUT replaces the whole record, that the tool reads-then-merges so only passed fields change (with the merge/replace split spelled out), and that items are sent back intact. It does not mention auth/permission requirements or failure modes, keeping it short of 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?

Front-loads the operation type and resource, then builds outward to merge semantics, folder behavior, and endpoint. Dense but each clause carries information; the parenthetical is long but earns its place by disambiguating merge vs replace.

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 11-parameter destructive mutation with nested objects and no output schema, the description covers the operation model, the merge behavior, and the sibling routing. Gaps remain on permissions/auth and on the non-address scalar fields, but the critical decision-relevant context is present.

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?

With only 45% schema coverage, the description must compensate, and it does for the important part: it clarifies that shipping/customer address fields and checkout_data/order_metadata keys are merged while other values are replaced. It leaves email, tax_total, handling_total, payment_status, shipping_total, and shipping_method semantics to the schema, which is a partial but meaningful compensation.

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?

Opens with 'WRITE: change fields of an existing order' – a specific verb, resource, and operation type that an agent can immediately distinguish from create_order, get_order, and the item/inventory siblings. The trailing 'PUT /orders/{order_id}' anchors it to a concrete endpoint.

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?

Explicitly routes folder changes to orderdesk_move_orders ('use orderdesk_move_orders to move it'), which is a clear when-not/alternative signal. It also frames the merge semantics that govern usage, but never states when to prefer create_order or how this differs from bulk operations beyond the folder case.

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