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

With no annotations, the description carries the full burden. It discloses that authentication is required and specifies the returned data scope, but does not explicitly state read-only nature, rate limits, or other behavioral traits. The 'Get' verb implies non-mutating, but it is not explicit.

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 sentences with no filler. The first sentence states the purpose and content, the second gives usage guidance and authentication. Every word earns its place, front-loaded efficiently.

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?

Given the tool's simplicity (no parameters, no output schema), the description is complete enough. It tells what information is returned and when to use it, covers authentication, and provides enough context for an AI agent to invoke it correctly. Minor lack of response format or error handling details, but not critical.

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?

The input schema has zero parameters, so schema coverage is 100%. Per the rubric for 0 params, baseline is 4. The description adds no parameter-related detail because none is needed, but it does not detract from 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 the tool retrieves account details, including current plan, QR code usage, and feature availability. It uses a specific verb ('Get') and resource ('account details'), and the content distinguishes it from sibling tools focused on individual QR codes or scans.

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 provides explicit when-to-use guidance: 'Use this before create_qr_code to check remaining capacity, or to confirm which features are active on your plan.' It lacks when-not or alternative tool references, but the primary use case is clear.

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