mcp-whatsapp

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

The description does not contradict annotations. Annotations indicate this is a destructive, non-idempotent, open-world write operation (readOnlyHint: false, destructiveHint: true, idempotentHint: false, openWorldHint: true). The description adds context by specifying it marks messages as read, which aligns with the destructive hint (changing message state) and open-world hint (operating on external WhatsApp data). It does not detail rate limits or auth needs, but annotations cover core behavioral traits.

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 a single, clear sentence that directly states the tool's purpose without unnecessary words. It is front-loaded and efficiently conveys the essential information, with no wasted text.

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 has annotations covering key behavioral traits (destructive, non-idempotent) but no output schema, the description is minimally complete. It specifies the action and resource but lacks details on return values or error conditions. For a mutation tool with annotations, this is adequate but leaves some contextual gaps.

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?

Schema description coverage is 67% (2 of 3 parameters have descriptions). The description does not add any parameter-specific information beyond what the schema provides (e.g., it doesn't explain the format of message_ids or when sender_jid is required). With moderate schema coverage, the baseline score of 3 is appropriate as the description does not compensate for gaps.

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 ('Mark message IDs as read') and the resource ('in a chat'), distinguishing it from sibling tools like 'mark_chat_read' (which marks an entire chat as read) and 'delete_message' (which removes messages). It uses precise terminology that aligns with the tool's function.

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 implies usage for marking specific messages as read in chats, but does not explicitly state when to use this tool versus alternatives like 'mark_chat_read' or other message-related tools. It provides clear context but lacks explicit exclusions or named alternatives.

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