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

Annotations already declare readOnlyHint=false, idempotentHint=false, destructiveHint=false, and openWorldHint=true, so the safety profile is partially covered. However, the description adds nothing beyond the annotations: it doesn't say whether the session drops, whether in-flight messages are lost, whether a QR re-scan is required, or how long the restart takes — all important for a disruptive operation.

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 short phrase with the verb front-loaded and zero filler. It is efficiently sized, though arguably too terse for a state-changing operation.

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 one-parameter, annotation-covered tool this is minimally sufficient — the agent knows what to call and with which ID. Missing are the operational consequences of a reboot (session loss, downtime, need to reconnect), which matter for correct invocation sequencing.

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?

There is only one parameter (instance_id) and schema coverage is 100%, so the schema fully documents it. The description adds no extra meaning about the identifier (e.g., where to obtain it via whatsapp_get_instances), so baseline 3 applies.

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 specific verb (reboot) and a specific resource (the WhatsApp instance), which an agent can read at a glance. It does not distinguish the operation from nearby siblings such as whatsapp_disconnect, whatsapp_logout, or whatsapp_connect, so the boundary between reboot and those alternatives is left implicit.

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 indication of when to reboot versus disconnect/logout/connect, nor any prerequisites such as an active session or whether the instance must be in a particular state. 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.