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

No annotations exist, so the description carries the full burden and does well: it discloses that the operation is out-of-band (user must open a link and scan), that it links a REAL phone number, that it is asynchronous and must be polled to completion, and that it costs nothing ('Free'). That covers side effects, workflow shape and cost — the traits an agent most needs.

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?

Three compact sentences, front-loaded with the return value and the user action, then the polling step, then the precondition. Every clause carries distinct operational information; nothing is repeated from the title or schema.

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?

With no output schema and no parameters, the description must supply return shape, user-side steps, completion check and cost — and it does all four. An agent can execute the whole flow from this text alone without opening another definition.

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?

Zero parameters, so the baseline is 4; there is nothing the description could add. Its mention of the returned link is output information rather than parameter guidance, which is appropriate here.

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 concrete verb and artifact ('Returns a hosted link') plus the exact user action that completes it (scan QR code via WhatsApp Linked devices). It also names the real-world effect — linking an actual phone number to the workspace — which separates it from siblings like connect_telegram_bot or connect_linkedin_account.

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?

Explicit gating: 'Only after preview_connect_whatsapp_account and the user's approval' names the required predecessor tool and the consent condition. It also names the follow-up tool (list_whatsapp_accounts) and the success state to poll for ('ok'), leaving nothing to inference.

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