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

Beyond the annotations (read-only, idempotent, non-destructive), the description explicitly discloses what results include and exclude — operational status and phone metadata but never secrets, QR codes, API keys, or arbitrary fields. This is valuable context not present in annotations.

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 well-structured sentence front-loads the action and resource, then adds the filter and result scope. Every clause adds information, with no filler or redundancy.

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?

An output schema exists, so return format is handled elsewhere. The description covers scope, filtering, and exclusions, which is sufficient for a list operation. It could have mentioned that pagination uses cursor/limit, but those are already described in the schema.

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 100%, so the schema already documents all three parameters. The description adds minimal value here, only reinforcing the project filtering concept already present in the projectId schema description.

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 uses a specific verb ('List') and a specific resource ('tenant-scoped Wapiworld WhatsApp instances'), and adds scoping details (bounded page, optional project filter). It clearly distinguishes itself from singular siblings like get_instance and get_instance_status.

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?

The description states the operation's scope and the optional project filter, giving clear context for when to call it. However, it does not explicitly contrast with alternatives such as get_instance for a single instance or get_instance_status for status-only retrieval.

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