mcp-wacli

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states the action ('Add participants') but doesn't mention critical behavioral aspects such as required permissions (e.g., admin rights in the group), rate limits, error conditions (e.g., if users are already members), or what happens on success/failure. This leaves significant gaps for safe and effective use.

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 appropriately sized and front-loaded, with the core purpose stated first ('Add participants to a WhatsApp group.') followed by parameter explanations. There's minimal waste, though the 'Args:' section could be integrated more smoothly. Overall, it's efficient and easy to scan.

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 complexity of a mutation tool (adding users to a group) with no annotations and no output schema, the description is incomplete. It lacks information on permissions, error handling, return values, and differentiation from sibling tools. This makes it inadequate for reliable agent use without additional context or trial-and-error.

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?

The schema description coverage is 0%, so the description must compensate. It adds basic semantics by explaining that 'jid' is the 'Group JID' and 'users' are 'List of phone numbers or JIDs to add', which clarifies the parameter types beyond the schema's generic string/array. However, it doesn't provide format details (e.g., JID structure, phone number format) or constraints, leaving some ambiguity.

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 verb ('Add') and resource ('participants to a WhatsApp group'), making the purpose immediately understandable. However, it doesn't explicitly differentiate from sibling tools like 'group_join' or 'group_participants_remove', which would require more specific language about adding external users versus joining oneself or removing participants.

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 like 'group_join' (for joining oneself) or 'group_participants_remove' (for removing participants). It lacks context about prerequisites (e.g., needing admin permissions) or exclusions, leaving the agent to infer usage from the tool name alone.

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