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

Annotations establish this is a non-destructive mutation (readOnlyHint=false, destructiveHint=false), and the description adds value beyond them: the required orders:write scope and the downstream effect that the paying buyer sees the document via shop.order.get. It does not cover idempotency or duplicate-attachment behavior, 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?

A single front-loaded sentence with the action verb first, and every clause (format constraint, examples, permission, downstream visibility) carries distinct information. No filler.

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 simple two-parameter attach action with an output schema already defined, the description covers purpose, auth, and effect adequately; return values need not be described. The only gap is order_id semantics, which is minor given its name.

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 0%, so the description carries the burden and does partially compensate: it constrains url to an https:// link with examples, which the bare 'string' type does not. However, order_id receives no semantic treatment beyond 'your order', leaving one of two parameters unexplained.

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 (Attach) and resource (an https:// link/document) applied to an order, with concrete examples (invoice, receipt). It also names shop.order.get as the surface where the effect is visible, so the agent can place it relative to the read side of the workflow.

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 gives the precondition (needs orders:write) but no explicit when-to-use vs. alternatives and no exclusions. The closest sibling it names, shop.order.get, is referenced as the visibility surface rather than as a competing tool, so routing guidance is only implied.

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