mcp-whatsapp

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

Annotations indicate destructiveHint=true and idempotentHint=false, suggesting this tool may cause side effects and isn't safe to retry. The description adds minimal behavioral context beyond this, as it doesn't explain what 'destructive' means in practice (e.g., if it affects chat state or user notifications). However, it doesn't contradict annotations, so it earns a baseline score for not adding much value beyond 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: 'Set typing/recording presence for a chat.' It's front-loaded with the core action and resource, with zero wasted words. This makes it easy for an agent to parse and understand quickly.

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?

For a tool with 3 parameters, 100% schema coverage, and annotations covering safety (destructive, non-idempotent), the description is minimally adequate. It lacks output schema, so return values aren't explained, but annotations provide some behavioral context. However, it doesn't fully compensate for missing usage guidelines or detailed behavioral traits, making it just sufficient.

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 descriptions for each parameter (e.g., 'active' as boolean for composing/paused, 'chat_jid' with WhatsApp JID formats, 'kind' for text/audio). The description doesn't add extra meaning beyond the schema, such as explaining parameter interactions or default behaviors. Given high schema coverage, a baseline score of 3 is appropriate.

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 tool's purpose: 'Set typing/recording presence for a chat.' It specifies the action ('Set') and the resource ('typing/recording presence for a chat'), making it easy to understand what the tool does. However, it doesn't explicitly differentiate from sibling tools like 'send_presence', which might have overlapping functionality, keeping it from a perfect score.

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 provides no guidance on when to use this tool versus alternatives. It doesn't mention sibling tools like 'send_presence' or clarify specific scenarios for setting typing vs. other presence states. Without such context, the agent must infer usage, which is a significant gap.

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