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

With no annotations, the description carries the burden well: it declares read-only behavior, result ordering, credential requirements, and the claimed-workspace gate including the 403 refusal. It does not describe pagination or return shape, but it discloses the key operational constraints.

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?

It is short and front-loaded: the action and ordering come first, then the argument, safety, and prerequisite constraints. Every sentence adds distinct operational information.

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 one-parameter read-only list tool with no output schema, the description covers purpose, ordering, required parameter, auth, and workspace prerequisites. It could say more about what a line item contains, but nothing critical to correct invocation is missing.

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 100%, and the single order_id parameter is documented in the schema. The description only repeats 'pass order_id' and adds no format or sourcing detail beyond what the schema already says ('as list_orders shows it').

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 gives a specific verb and resource - 'List the line items on an order' - and states the ordering ('oldest first'). That is enough for an agent to distinguish it from sibling list_orders and get_order without needing more routing text.

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?

It states the required argument and two concrete prerequisites: a Last Price credential and a claimed workspace, with the explicit failure mode for unclaimed sandbox keys (403). It does not name an alternative tool for related order data, so it stops short of full when-vs-what guidance.

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