Get login QR

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

With no annotations provided, the description carries the full burden. It discloses what the tool returns and when it's needed, but does not mention potential side effects such as whether requesting a new QR code invalidates previous ones, session expiry, or whether this initiates a pairing session on WhatsApp's side.

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 zero wasted words. The core function is front-loaded in sentence one, and the usage condition is added in sentence two. Perfectly sized for a zero-parameter tool.

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 tool of this low complexity (0 params, no output schema), the description covers the essentials: what it returns and when it's needed. Minor gaps include the output format (image, URL, or data URI) and QR expiry behavior, but nothing an agent needs to invoke it correctly 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?

The tool has zero parameters, so the schema documents everything there is to know. Per the rubric, 0 params earns a baseline of 4; the description has nothing to add about parameters and doesn't need to.

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 ('Returns'), a specific resource ('the QR code'), and the exact purpose ('to link this device to a WhatsApp account'). It is naturally differentiated from all siblings because no other tool in the list handles authentication or QR codes.

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?

Gives explicit usage timing: 'Only needed the first time, or after being logged out.' This tells the agent when the tool is appropriate and implies it should not be used when already logged in, though it doesn't name alternatives (none exist among siblings).

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