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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, openWorldHint=false), so the bar is lower. The description still adds two pieces of real context: it only yields proof for an already-delivered delivery, and sandbox proofs are explicitly marked simulated — data-trust information that the annotations do not convey.

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?

Two short sentences with no filler, and the core identification comes first. It is arguably too terse rather than bloated, but nothing in it is wasted or redundant.

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?

With no output schema, the description does carry some return-content information (store_id, order_ref, simulated marking), which is useful. But it omits any treatment of the required delivery_id, the version enum, or behavior when the delivery is not yet delivered, leaving meaningful gaps for a 2-parameter tool.

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 description coverage is 0% across 2 parameters, so the description must compensate and it does not. It names store_id and order_ref, which are result fields rather than inputs, while delivery_id (required, UUID) and the robomart_version enum are never mentioned, leaving the agent without meaning for either input.

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 identifies the resource ('proof of a delivered Delivery') and the content it carries (store_id, order_ref), so an agent can infer this retrieves proof-of-delivery records. However it is a noun fragment with no explicit verb for the action, and it does nothing to distinguish itself from the adjacent sibling track_delivery.

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?

There is no when-to-use guidance and no named alternative. The phrase 'of a delivered Delivery' implies a state precondition (the delivery must already be delivered), but this is left to inference and no sibling such as track_delivery is offered as a contrast.

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