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, but the description adds context by specifying it fetches 'live group metadata' and returns JSON, clarifying it's a read operation despite the annotations. This resolves potential confusion, though it doesn't detail side effects like rate limits or authentication needs.

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 a single, efficient sentence, followed by a brief note on the return format. Every word contributes value without redundancy, 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 (fetching group metadata), lack of output schema, and annotations with potential contradictions (destructiveHint for a read operation), the description is adequate but incomplete. It clarifies the read nature and output format but omits details like error handling, response structure, or how it differs from similar tools, leaving gaps for the agent.

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%, fully documenting the 'chat_jid' parameter with WhatsApp JID formats. The description adds no additional parameter details beyond implying it's for groups, which is already covered in the schema. Baseline 3 is appropriate as the schema handles all parameter semantics.

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 action ('Fetch'), resource ('live group metadata'), and scope ('for the given group JID'), distinguishing it from siblings like 'get_chat' or 'list_groups' by specifying group-specific metadata. However, it doesn't explicitly differentiate from 'get_group_invite_link' which also retrieves group-related information.

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 like 'get_chat' (for general chat info) or 'list_groups' (for group listings). The description lacks context about prerequisites, such as needing a valid group JID, or exclusions, leaving the agent to infer usage from the tool name and parameters alone.

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