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

readOnlyHint=true already tells the agent this is a safe, non-mutating call. The description adds genuinely new context: the link pre-populates a standard enquiry message and varies by channel. It says nothing about the returned link's structure, whether the message is customizable, or that nothing is persisted.

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?

A single front-loaded sentence with the verb first and no filler; every clause (three link types, standard message, shop + optional item) carries information. Slightly run-on but appropriately sized.

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, no enums, and 0% schema coverage on 4 parameters, the description should explain the missing parameters and roughly what the returned link looks like. It omits two parameters entirely and says nothing about the return value, leaving real gaps for an agent.

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 description coverage is 0% across 4 parameters, so the description must carry the semantic load. It maps shop_slug and item_id ('for a shop and optional item') but leaves customer_note and preferred_time entirely unexplained, and adds no format or constraint detail for the two it does mention.

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 (Generate) plus the outputs it produces (WhatsApp deep link, booking URL, phone dial link) scoped to a shop and optional item. That is unambiguous and unlike the sibling tools (find_shops, get_catalog, search_catalog), though it never explicitly contrasts itself with them.

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?

Usage is only implied: it is clear this is for producing a contact/enquiry link for a shop, and it notes a 'standard customer enquiry message' is attached. There is no statement of when to prefer this over siblings or any precondition (e.g., shop must exist, link is shareable vs clickable).

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