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

Annotations already cover the safe read profile (readOnlyHint=true, destructiveHint=false), so the bar is lower. The description adds real context beyond them: credentials and endpoint URLs are hidden, and the call requires the whatsapp_agents:read scope. That privacy and auth detail is genuinely useful.

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 tight sentences, front-loaded with the purpose, followed by the output caveat and then the enablement workflow. Every sentence carries information an agent needs.

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?

With an output schema present, return values need not be described, and the description still flags what is returned (configuration and IDs) and what is hidden. For a no-param read tool the definition is complete enough to call correctly.

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 tool takes zero parameters, so there is nothing for the description to disambiguate; the baseline for a no-param tool is 4. The description does not need to explain any inputs, and the 100% schema coverage leaves no gap.

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 ('List') and resource ('the organization's WhatsApp tool library'), plus the content returned ('configuration and IDs'). This distinguishes it cleanly from siblings like list_whatsapp_tool_sources and save_whatsapp_tool.

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?

Gives a clear follow-on workflow: read the target agent, then call update_whatsapp_agent with updates.externalToolIds as the full selected ID list. This tells the agent why and how to use the output. It does not explicitly contrast with the other list_* siblings, so it stops short of a 5.

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