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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and closed-world, so the safety profile is covered. The description adds nothing beyond that — no return shape, no indication of whether the list is paginated, cached, or requires an active session, which is the remaining burden for a bare read.

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?

The description is a single short sentence with no waste, but its brevity stems from under-specification rather than disciplined editing. It is front-loaded but carries almost no information.

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 simple single-parameter read tool with full annotation coverage and no output schema, the description does just enough for an agent to call it correctly. The main missing element is an explicit statement of what the list contains or how it relates to the per-contact sibling tools.

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?

Only one parameter (instance_id) exists and schema description coverage is 100%, so the baseline is 3. The description adds no meaning about the parameter beyond what the schema provides.

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 phrase 'Get the contact list' names a verb and a resource, so the basic purpose is legible. However, with siblings like whatsapp_get_contact_info and whatsapp_get_contact_avatar present, the description never explicitly states that this returns the full list rather than details of one contact, leaving the distinction to inference.

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?

There is no guidance on when to use this over whatsapp_get_contact_info or whatsapp_get_contact_avatar, and no prerequisites such as the instance needing to be connected. The agent must infer usage entirely from the name.

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