mcp-whatsapp

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

Annotations indicate destructiveHint=true and readOnlyHint=false, which the description aligns with by implying a download operation that likely writes to local storage. The description adds value by specifying the return type ('local file path'), which annotations do not cover. However, it does not detail potential side effects like file overwriting or storage limits.

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, efficient sentence that front-loads the core action and outcome. Every word earns its place, with no redundant information or fluff, making it highly concise and well-structured.

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 moderate complexity (2 required parameters, destructive operation), the description covers the essential purpose and output. However, without an output schema, it could benefit from more details on error handling or file format specifics, though annotations provide good behavioral 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?

Schema description coverage is 100%, providing clear details for both parameters (chat_jid and message_id). The description does not add any parameter-specific information beyond what the schema already documents, so it meets the baseline score of 3 without compensating further.

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 ('Download media from a WhatsApp message') and the resource ('WhatsApp message'), distinguishing it from siblings like 'send_file' or 'get_message_context'. It explicitly mentions the return value ('return the local file path'), which is not obvious from the tool name alone.

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 when media needs to be downloaded from a WhatsApp message, but it does not explicitly state when to use this tool versus alternatives (e.g., 'get_message_context' for metadata or 'send_file' for uploading). No exclusions or prerequisites are mentioned, leaving the context somewhat open-ended.

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