Get the WhatsApp login QR code as a PNG image to scan from your phone's Linked devices. Use only while logged out; each code expires in about a minute.
Get the login QR code as a PNG image, to scan from WhatsApp on the phone (Linked devices). Only works while logged out, and each code expires within about a minute. Returns the image.
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds genuinely useful behavioral context beyond the annotations: the precondition (must be logged out) and the short-lived nature of the credential ('each code expires within about a minute'), which affects how the caller must sequence and consume the result.
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, no filler, and the essential facts (what it returns, how it's used, the precondition, the expiry) are all front-loaded before the closing redundancy about the return value.
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 no-param, no-output-schema tool the description covers what is returned (a PNG), how to use it (scan from the phone), and the constraint that it only functions while logged out. Minor gap: it doesn't mention how to handle the returned binary or that a fresh call is needed after expiry.
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 takes zero parameters and the schema is empty with 100% coverage, so there is nothing for the description to disambiguate; the baseline for a no-param tool applies.
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+resource ('Get the login QR code') and specifies the output medium (PNG image), which distinguishes it from the sibling whatsapp_get_qr_code that presumably returns the code in text form. It does not explicitly name that sibling, so the differentiation is implicit rather than stated.
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 a clear precondition — 'Only works while logged out' — and the intended workflow ('to scan from WhatsApp on the phone (Linked devices)'). It does not, however, route the agent between this tool and the alternatives whatsapp_get_qr_code / whatsapp_get_pair_code when the linking flow fails or a different code format is wanted.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.