mcp-wacli

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It states the tool shows contact details but doesn't mention whether this is a read-only operation, what permissions are required, what happens if the JID is invalid, or the format of the returned details. For a tool with zero annotation coverage, this is a significant gap in transparency.

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 the first sentence, followed by parameter details in a structured 'Args:' section. It's efficient with minimal waste, though the parameter explanation could be slightly more detailed to improve clarity without sacrificing brevity.

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 (a read operation with one parameter), lack of annotations, and no output schema, the description is incomplete. It doesn't explain what details are returned, error conditions, or how this tool relates to siblings like 'search_contacts'. For adequate contextual understanding, more information is needed.

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 description adds value by explaining the 'jid' parameter with an example format ('573001234567@s.whatsapp.net'), which the schema (with 0% description coverage) does not provide. However, it doesn't clarify what a JID is, how to obtain it, or validate it, leaving some semantic gaps. With low schema coverage, this partial compensation earns a baseline score.

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 with a specific verb ('Show') and resource ('details of a single contact'), making it immediately understandable. However, it doesn't explicitly differentiate from sibling tools like 'search_contacts' or 'refresh_contacts', which would require a 5.

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 'search_contacts' or 'list_chats'. It lacks context about prerequisites (e.g., whether the contact must exist in the system) 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.