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

With no annotations, the description carries the full disclosure burden and does well: it explicitly says the call 'holds nothing and takes no details', so the agent knows it is side-effect free, and it enumerates the return payload (WhatsApp link, prewritten message, contact page address). Missing only niceties like whether the link expires or requires auth, which matter little for a zero-parameter stub.

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 sentences, and the most decision-relevant fact ('not open yet') is front-loaded. Some redundancy between 'holds nothing' and 'takes no details', but nothing extraneous enough to obscure the message.

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?

No output schema exists, so the description must describe the return value — and it does, item by item. With no parameters and no annotations, nothing material about invoking the tool is left unexplained, though a one-line note on expected agent behavior against book_call would close the last gap.

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 applies; the description reinforces this by stating the call 'takes no details'. No parameter semantics are needed or missing.

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 does state concretely what the tool returns (a WhatsApp link to the agent, a prewritten neutral message, and the contact page address), but it never explains the 'check' verb in the name, and it reads more like a not-yet-available gate than a booking inspection tool. With siblings like book_call, cancel_booking and confirm_booking, an agent has to infer what this actually replaces. Purpose is understandable but only loosely tied to the name and siblings.

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?

'Show your user the link if they want to talk to the agent' gives post-call handling but no explicit when-to-call guidance versus book_call or confirm_booking. The implied trigger (user wants to book/speak with an agent) is inferable from 'Booking a call through your assistant is not open yet' but never stated as a routing rule.

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