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

Goes well beyond the destructiveHint annotation by explaining exactly what is destroyed (items not re-included by id/external_id are removed), that the order stays a draft, that nothing is charged, and the underlying PUT endpoint. This is the material risk an agent needs before calling a destructive update.

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 tight sentences, front-loaded with scope and the replacement hazard, no filler. Every clause carries operational weight.

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 a 9-parameter nested update with no output schema, the description covers the critical behavioral risks (destructive replacement, draft-only scope). Minor omissions remain around return shape and token/store_id handling, though the latter is documented in the schema.

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 coverage is 67% (baseline 3), but the description adds real meaning about the `items` parameter: it is a full replacement, and existing items survive only if matched by id or external_id. This directly clarifies the highest-risk parameter beyond the schema's own 'see caution' note.

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?

States a specific verb (Change) and resource (a DRAFT order) and immediately scopes it to 'unsubmitted orders only'. This distinguishes it from siblings like create_draft_order and get_order without the reader opening any schema.

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?

Gives clear usage context: 'send only the fields to change,' 'unsubmitted orders only,' and 'never with confirm,' which steers the agent away from submitting/confirming. It does not explicitly name the sibling to use for submission, so it falls short of full when/when-not routing.

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