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

Annotations already declare readOnlyHint/idempotentHint true and destructiveHint/openWorldHint false, so the safety profile is covered. The description adds genuinely non-obvious behavior: the tool only constructs a message link, no order is placed, and the customer must manually send the message — exactly the misconception an agent would otherwise have.

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, each carrying distinct information, with the core purpose and the 'no order created' caveat front-loaded. Slightly dense parenthetical packing of the input modes, but nothing is wasted.

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, the description carries the burden of explaining the return value and does so: a WhatsApp link plus the page URL for the customer to order on the site. For a 3-parameter, zero-required-parameter tool this is nearly complete; only the role of 'quantity' in the message 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?

Schema coverage is 67%, so the schema already documents product ('URL or slug') and vip_number ('11 digits starting with 07'). The description adds a concrete VIP example (07855557555) and restates the product forms, but 'quantity' is never mentioned in either the schema or the description, leaving its effect on the generated message unexplained.

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 states a concrete verb and artifact ('Builds a WhatsApp link with a ready order message'), names the recipient (Baqer Store's sales team) and the two input modes (product URL/slug or VIP number). This is clearly distinguishable from read-oriented siblings like get_product and search_products, which fetch data rather than generate a customer-facing link.

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?

It gives a direct operational instruction ('Give the link to the customer') and pre-empts the most likely misuse by stating 'No order is created: the customer opens the link and sends the message.' It does not explicitly name an alternative tool or state when-not to use it, so it stops short of a full routing rule.

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