mcp-whatsapp

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

Annotations indicate destructiveHint=true and readOnlyHint=false, suggesting a potentially unsafe operation despite the 'list' verb. The description adds context by specifying it returns 'a JSON array of group info objects,' which clarifies output format. However, it doesn't explain why listing is destructive or address rate limits, making it good but not fully comprehensive.

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 front-loaded with the core purpose in the first sentence and adds essential output details in the second. Both sentences earn their place by providing critical information without redundancy or fluff.

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?

Given the tool's low complexity (0 parameters) and rich annotations, the description is mostly complete. It covers purpose and output format, but lacks context on why it's destructive or usage guidelines, leaving minor gaps in behavioral understanding.

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?

With 0 parameters and 100% schema description coverage, the baseline is 4. The description adds value by implicitly confirming no inputs are needed and specifying the output as a JSON array, which compensates for the lack of an output schema.

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 specific action ('List every WhatsApp group') and resource ('the paired user belongs to'), distinguishing it from siblings like 'list_chats' or 'get_group_info' by focusing exclusively on group membership enumeration rather than chat listing or individual group details.

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?

No guidance is provided on when to use this tool versus alternatives. It doesn't mention prerequisites (e.g., user pairing), exclusions, or compare it to similar tools like 'list_chats' (which might include non-group chats) or 'get_group_info' (for specific group details).

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