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

Annotations already declare readOnlyHint and idempotentHint, so the safety profile is covered. The description adds the critical behavioral insight that connected=false causes broadcasts to be preview-only and NOT delivered to real phones—context that affects downstream decisions and is not present in the 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?

Three front-loaded sentences with zero waste: purpose and return shape in the first, the key limitation in the second, and routing guidance in the third. Every sentence earns its place.

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 no-parameter, read-only status tool without an output schema, the description provides purpose, return fields, the real-world implication of the result, and explicit guidance to sibling tools. An agent has everything needed to decide whether and when to invoke it.

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?

The input schema is empty (zero parameters), so schema coverage is trivially 100%. With no parameters, the baseline of 4 applies; the description does not need to explain parameter details that do not exist.

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+resource combination ('Check whether this workspace has a connected WhatsApp number') and enumerates the returned fields the caller can expect. It also distinguishes itself from send_broadcast and whatsapp_connect_link by making clear it is a read-only status check, not an action.

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?

Explicitly instructs when to call this tool ('before send_broadcast if the user expects real delivery') and provides an alternative path ('if not connected, use whatsapp_connect_link'). The consequence of the false case (preview only, no real delivery) reinforces why the agent needs to check this first.

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