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

The description goes beyond annotations by explaining that the operation is not read-only and can change the order's state by advancing it if not ready. This is a non-obvious behavioral trait not captured by readOnlyHint=false, adding real value.

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?

The description is two short sentences with no filler. The main purpose is front-loaded, and the critical caveat about side effects is placed clearly without excess wording.

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 single-parameter tool with an output schema and complete annotations, the description fully covers what the agent needs: what it does, the side-effect warning, and the input type. No critical information 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 description coverage is 100% for the single order_id parameter, which already states 'order_id of a fulfilled order'. The description adds no additional semantic detail beyond the schema's text, so it stays at the baseline.

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 clearly states it retrieves 'the QR code and activation details for a purchased eSIM'. This is a specific verb+resource combination that distinguishes it from sibling tools like get_esim_usage and get_order_status.

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 provides explicit context: states the tool is not read-only and can advance an order's state, comparing it to get_order_status. This informs when to use it and warns about side effects, though it doesn't explicitly list alternatives.

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