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

Annotations already declare this is a non-read-only, non-idempotent, non-destructive create operation. The description adds useful behavioral context beyond that: scans are tracked, they route to destination_url, and each mailed postcard can have its own code for per-recipient tracking.

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 short and front-loads the main action in the first sentence. The second sentence usefully explains the next step, though the phrase 'under it' is slightly ambiguous.

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 create tool with fully described parameters and clear annotations, the description covers purpose, tracking behavior, and the related postcard workflow. It does not describe the return value, but with no output schema and a straightforward create operation, that omission is not severe.

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%, so all four parameters are already documented with examples and constraints. The description only repeats that destination_url receives scans and does not add new syntax or selection guidance for name or color parameters.

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 states a specific verb (Create) and resource (tracked QR code), and explains the core behavior that scans are sent to destination_url. It also names the related postcard workflow tool, making its role distinct from spur_add_postcard_qr_code.

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 clearly indicates the intended workflow: create the QR code here, then attach it to a postcard with spur_add_postcard_qr_code. It does not explicitly state when not to use it or name alternatives such as spur_update_qr_code, so it stops short of full usage guidance.

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