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

Annotations already declare read-only, idempotent, and non-destructive behavior. The description adds transparency by specifying the exact data returned, which goes beyond the annotations. No contradictions.

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 concise and directly conveys the essential information. It uses a clear format with an em dash to list returned fields, making it highly efficient without unnecessary words.

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?

The description covers the tool's purpose and return fields, but does not explain the 'account' parameter or any prerequisites (e.g., authentication). Given the low complexity and minimal schema, it is mostly complete but lacks parameter context.

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 includes a single 'account' parameter of type string without any description. The tool description does not explain its purpose (e.g., filter, identifier, optional), leaving the parameter semantics ambiguous.

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 clearly states the tool's purpose: listing WhatsApp accounts paired to the install. It also specifies the fields returned (wa_jid, phone, label, proxy status, account status), making it highly specific and easy to distinguish from sibling tools.

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 implicitly indicates when to use the tool (when you need to list paired WhatsApp accounts) and there is no ambiguity among siblings. However, it does not explicitly compare with alternatives or mention any prerequisites, but given uniqueness, it is adequate.

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