mcp-whatsapp

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

Annotations indicate this is a destructive, non-idempotent, open-world write operation. The description adds value by specifying the target types (person/group) and formats (phone number/JID), which are not covered by annotations. It does not contradict annotations, as 'send' aligns with destructiveHint=true and readOnlyHint=false, and provides useful contextual details beyond the structured data.

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 target, with no wasted words. It directly communicates the essential information without redundancy or unnecessary elaboration, 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 complexity (destructive write operation with 3 parameters), annotations provide good behavioral context, and the schema fully documents inputs. The description adds necessary target semantics, but lacks output details (no output schema) and could benefit from more usage guidance. It is mostly complete but has minor gaps in contextual richness.

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%, with clear documentation for all parameters (recipient, message, mark_chat_read). The description adds minimal semantics by mentioning 'phone number or JID' and 'group (JID)', which slightly elaborates on the recipient parameter but does not significantly enhance the schema's thorough documentation. Baseline 3 is appropriate given high schema coverage.

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 ('Send a WhatsApp message') and the target resources ('to a person (phone number or JID) or group (JID)'). It distinguishes this tool from siblings like send_audio_message, send_file, send_poll, etc., which send different content types, making the purpose unambiguous and well-differentiated.

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 sending text messages via WhatsApp, but provides no explicit guidance on when to use this tool versus alternatives like send_audio_message or send_file, nor does it mention prerequisites or exclusions. The context is clear but lacks comparative direction.

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